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Clinical Linguistics

Summary and Keywords

Clinical linguistics is the branch of linguistics that applies linguistic concepts and theories to the study of language disorders. As the name suggests, clinical linguistics is a dual-facing discipline. Although the conceptual roots of this field are in linguistics, its domain of application is the vast array of clinical disorders that may compromise the use and understanding of language. Both dimensions of clinical linguistics can be addressed through an examination of specific linguistic deficits in individuals with neurodevelopmental disorders, craniofacial anomalies, adult-onset neurological impairments, psychiatric disorders, and neurodegenerative disorders. Clinical linguists are interested in the full range of linguistic deficits in these conditions, including phonetic deficits of children with cleft lip and palate, morphosyntactic errors in children with specific language impairment, and pragmatic language impairments in adults with schizophrenia.

Like many applied disciplines in linguistics, clinical linguistics sits at the intersection of a number of areas. The relationship of clinical linguistics to the study of communication disorders and to speech-language pathology (speech and language therapy in the United Kingdom) are two particularly important points of intersection. Speech-language pathology is the area of clinical practice that assesses and treats children and adults with communication disorders. All language disorders restrict an individual’s ability to communicate freely with others in a range of contexts and settings. So language disorders are first and foremost communication disorders. To understand language disorders, it is useful to think of them in terms of points of breakdown on a communication cycle that tracks the progress of a linguistic utterance from its conception in the mind of a speaker to its comprehension by a hearer. This cycle permits the introduction of a number of important distinctions in language pathology, such as the distinction between a receptive and an expressive language disorder, and between a developmental and an acquired language disorder. The cycle is also a useful model with which to conceptualize a range of communication disorders other than language disorders. These other disorders, which include hearing, voice, and fluency disorders, are also relevant to clinical linguistics.

Clinical linguistics draws on the conceptual resources of the full range of linguistic disciplines to describe and explain language disorders. These disciplines include phonetics, phonology, morphology, syntax, semantics, pragmatics, and discourse. Each of these linguistic disciplines contributes concepts and theories that can shed light on the nature of language disorder. A wide range of tools and approaches are used by clinical linguists and speech-language pathologists to assess, diagnose, and treat language disorders. They include the use of standardized and norm-referenced tests, communication checklists and profiles (some administered by clinicians, others by parents, teachers, and caregivers), and qualitative methods such as conversation analysis and discourse analysis. Finally, clinical linguists can contribute to debates about the nosology of language disorders. In order to do so, however, they must have an understanding of the place of language disorders in internationally recognized classification systems such as the 2013 Diagnostic and Statistical Manual of Mental Disorders (DSM-5) of the American Psychiatric Association.

Keywords: aphasia, cleft lip and palate, communication disorder, dysarthria, hearing loss, language disorder, schizophrenia, specific language impairment, speech-language pathology, speech sound disorder

1. The Scope of Clinical Linguistics

Clinical linguistics is the branch of linguistics that applies linguistic concepts and theories to the study of language disorders. As its name suggests, clinical linguistics is a dual-facing discipline. Although the conceptual roots of this field are in linguistics, its domain of application is the vast array of clinical disorders that may compromise language. This article will address both dimensions of clinical linguistics. Like many applied disciplines in linguistics, clinical linguistics sits at the intersection of a number of areas. Below, its relationship to speech-language pathology and communication disorders is briefly explored. In section 2, “The Communication Cycle,” language disorder is conceptualized in terms of points of breakdown on a communication cycle. This cycle will permit the introduction of important clinical distinctions, such as the distinction between a receptive language disorder and an expressive language disorder. In section 3, “Language Disorders and Linguistic Disciplines,” a number of language disorders are discussed and illustrated with the use of linguistic data. This section will emphasize the contribution of the full range of linguistic disciplines to the characterization of language disorder: phonetics, phonology, morphology, syntax, semantics, pragmatics, and discourse. By the end of the article, readers will have a wide-ranging understanding of the work of clinical linguistics.

For most people, language is acquired without difficulty or effort during the developmental period. However, for a significant number of individuals with developmental disorders, language acquisition is anything but effortless. For an equally large number of individuals, language may be disrupted for the first time in adulthood as a result of illness, injury, or disease. When language skills are not acquired along normal lines or are impaired in adulthood, language disorders are the result. While the linguistic features of these disorders are of inherent interest to clinical linguists, it is ultimately speech-language pathologists (speech and language therapists in the United Kingdom) who must assess and treat clients with these disorders. Children and adults with language disorders face considerable social, economic, vocational, and academic challenges as a result of these disorders (Cummings, 2011; 2014). The purpose of the clinical language services that are offered in speech-language pathology (SLP) is to mitigate the adverse effects of language disorders and, by so doing, improve the quality of life and opportunities of individuals with language disorders. Speech-language pathology has substantial success in both of these areas. For our present purposes, SLP is the area of clinical practice where the clinical linguist’s theoretical knowledge of language disorders informs the assessment and treatment of clients with these disorders. Speech-language pathology is so integral to the management of language disorders that studying clinical linguistics in the absence of SLP is tantamount to studying language disorders in the absence of the individuals who experience these disorders. Neither is a logical or meaningful pursuit.

Clinical LinguisticsClick to view larger

Figure 1. The interrelationships between clinical linguistics, speech-language pathology, and communication disorders.

The child or adult with impaired language skills may be unable to initiate a conversation with a friend, ask for and understand directions from a stranger, or follow an explanation in the classroom or the workplace. In other words, language disorders are significant for the reason that they compromise an individual’s ability to communicate with others across a wide range of contexts and settings. Language disorders are thus a type of communication disorder. But communication may also be impaired on account of a hearing disorder, speech disorder, fluency disorder, or voice disorder. These other impairments of communication are also assessed and treated by speech-language pathologists. Several have relevance to language pathology. For example, the child with cleft lip and palate, who has a speech disorder, often has an associated language disorder, while there are clear linguistic influences (e.g., word and utterance length effects) on the rate of dysfluencies in the fluency disorder, on the rate of dysfluencies in developmental stuttering. In short, many clinical linguists cast the net of their discipline much more widely than simply language disorders to include speech disorders, fluency disorders, and other groups of communication disorders. This is indicated in Figure 1 through the use of a dashed line to indicate a permeable boundary around clinical linguistics. On narrow definitions of clinical linguistics, only language disorders fall within this boundary, while on broader definitions, several other groups of communication disorders may also be included. Clinical linguistics, speech-language pathology, and communication disorders are so intimately interwoven that in practical terms at least, it is difficult to draw a clear line of demarcation between these domains.

2. The Communication Cycle

The production and comprehension of linguistic utterances are among our most complex cognitive abilities. As a route to understanding these processes, this section outlines a cyclical model of human communication. This model leads readers through a series of eight somewhat simplified stages, from the point at which a speaker first entertains a thought or an idea to be communicated, to the point where a hearer or listener may be said to have understood the speaker’s utterance. Having introduced each of the stages, we return to the beginning of the cycle and revisit each stage, locating a range of language and communication disorders along the way. By the end of the section, readers will have a sound understanding of the different ways in which language disorders may arise and of their impact on communication.

Communicative intentions are the starting point of any act of communication. Speakers and writers entertain many more thoughts than they can ever (or should ever) express. For a thought to become a communicative intention, speakers must believe that there is some purpose or value in the thought being expressed, and believe that their hearers believe that there is some purpose or value in the thought being expressed. That value may be to contribute an interesting detail to a story, to bring a new angle to the resolution of a problem, or to express an opinion in a moral or ethical debate. Aside from satisfying a particular purpose or value, communicative intentions must also conform to social norms about what is appropriate to communicate in certain contexts. Speakers who fail to make appropriate selections of communicative intentions according to social norms quickly experience the disapprobation of their peers. Once selected, a communicative intention must assume a form whereby it can be transmitted from speaker to hearer. More often than not, this form is a linguistic code that is meaningful to a community of language users. As well as sounds, letters, and words in spoken and written utterances, a linguistic code may involve manual signs and symbols in American Sign Language or Makaton. (Makaton is a sign and symbol communication system that is designed to support spoken language.) The selection of the phonological, syntactic, and semantic structures that give expression to a communicative intention occurs during a stage in the communication cycle called language encoding.

The encoded utterance is an abstract linguistic representation that is still not of a form that can be communicated to a hearer. Planning of the motor movements that will be needed to achieve communication of the utterance occurs during motor programming. The articulatory gestures and other vocal tract configurations, which are needed to produce the utterance, are selected and arranged in a program that oversees the temporal and spatial dimensions of each movement. The final stage on an utterance’s journey to production is motor execution. During this stage, a series of neuromuscular events, which include nerve impulse transmission, results in the coordinated movement of articulators and other parts of the speech production system (e.g., respiratory muscles). If execution is successfully achieved, the result should be the fluent production of a linguistic utterance. Each of these stages in the production of an utterance is depicted in Figure 2.

Clinical LinguisticsClick to view larger

Figure 2. The human communication cycle.

Of course, a linguistic utterance is only meaningful to the extent that it is received by a hearer who can comprehend its significance. For this to occur, each stage in a speaker’s production of an utterance must be matched by a corresponding stage in a hearer’s comprehension of the utterance. During sensory processing, the sound waves that constitute the speech signal are converted by the middle ear into mechanical vibrations, and then by the inner ear into a series of neurophysiological events. These events result in nerve impulse transmission along the vestibulocochlear (acoustic) nerve to the auditory cortices of the brain. It is in the auditory cortices of the brain that recognition of incoming signals from the peripheral hearing mechanism is achieved by the hearer (National Institute on Deafness and Other Communication Disorders, 2015).

The recognition of speech sounds during speech perception is only partly based on the information that the brain receives from the ear’s processing of the speech signal. Perception also draws on other (top-down) sources of information, as demonstrated by the fact that we can still perceive spoken messages when the speech signal is incomplete or degraded. The outcome of speech perception is the input data for language decoding. During this stage of the communication cycle, the phonological, syntactic, and semantic structure of an utterance is unpacked, resulting in a logical form (at least on some accounts of the process). Sometimes, the logical form of an utterance is, simply, a speaker’s intended meaning. More often than not, however, the decoded utterance must undergo further (pragmatic) processing before the communicative intention that motivated the speaker to produce the utterance can be established. When this point is reached, communication has come full circle, and the hearer’s comprehension of the utterance aligns fully with the speaker’s intention in producing it. These receptive stages in communication are also shown in Figure 2.

For most individuals, the eight stages outlined above operate efficiently in supporting communication. However, for a substantial number of children and adults, these stages are impaired through injury, illness, disease, or neurodevelopmental anomaly. The adult with schizophrenia, for example, may generate communicative intentions that are not appropriate to a particular context or that violate social norms. The result may be the production of offensive or impolite remarks. The child with autism spectrum disorder (ASD) may have in mind a communicative intention that serves no purpose or value in a conversational exchange, such as when an utterance about trains is conveyed in response to a question about school. Even if an appropriate communicative intention is generated, this intention may not be successfully encoded in a linguistic utterance in an adult with aphasia or a child with specific language impairment (SLI). In these acquired and developmental language disorders, respectively, language encoding may be compromised on account of disruption to phonological, syntactic, and semantic structures.

The encoded utterance may fail at the point of motor programming in the adult with apraxia of speech (AOS). During programming, motor movements in persons with AOS may be arranged in the wrong order, leading to transposition errors (e.g., Africa → Arifca), or may be mistimed, resulting in the substitution of a voiceless sound by a voiced sound (e.g., pen → ben). Finally, planning of motor movements may take place normally, only for the motor execution of the utterance to go awry. The result may be inaudible speech in the adult with Parkinson’s disease and acquired dysarthria, or severely unintelligible speech in the child with cerebral palsy and developmental dysarthria.

Each of the above communication disorders disrupts the production or expression of linguistic utterances. Some of the same communication disorders can cause impairments of the comprehension or reception of utterances. In children and adults with hearing loss, the sensory processing of the speech signal may be impaired. This can occur in conductive hearing loss, where the mechanical transmission of sound waves through the middle ear may be compromised on account of otitis media (glue ear), and in sensorineural hearing loss as a result of noise-induced damage of hair cells in the cochlea, for example. Even when peripheral hearing is intact, hearers may fail to recognize or perceive the spoken form of words on account of auditory verbal agnosia, a condition that is often confused for deafness in children with the rare disorder Landau-Kleffner syndrome. (Auditory non-verbal agnosia is the inability to recognize environmental sounds, such as the bark of a dog.)

Assuming that speech perception is achieved, a hearer may still fail to decode linguistic utterances on account of impairments of phonology, syntax, and/or semantics. For example, an adult who develops aphasia following a stroke may be unable to decode the passive voice construction in the utterance ‘The ball was kicked by the boy.’ Finally, the same disorders that compromised the generation of appropriate communicative intentions may also disrupt the ability of a hearer to go beyond the processing of the logical form of an utterance to recover the communicative intention that motivated a speaker to produce the utterance. In this way, the child with ASD may be unable to establish that the utterance ‘Can you close the window?’ is a request to close the window, and that the idiomatic utterance ‘Don’t let the cat out of the bag!’ is a command to keep something secret.

3. Language Disorders and Linguistic Disciplines

Several language disorders were introduced in section 2. Disorders such as aphasia and SLI are related to a breakdown of language encoding and decoding, while the language impairments of individuals with schizophrenia and ASD additionally involve impairments in the generation and recovery of communicative intentions. What we did not address in any detail in section 2 were the linguistic deficits that can occur in these disorders and how different branches of linguistics may be used to characterize these deficits. To demonstrate the dependence of clinical linguistics on each of the disciplines of linguistics, this section examines a range of linguistic errors found in developmental and acquired language disorders. Although these errors are not exhaustive of the types of linguistic impairments that can occur, they illustrate the extent to which linguistic concepts and terms inform the work of clinical linguistics. Readers should be aware that even the description of linguistic impairments is not a theory-neutral activity, and that clinical linguistics is a field that is informed by diverse theoretical perspectives. The application of optimality theory to the study of phonological disorder in children, and the use of a relevance-theoretic framework to explain pragmatic impairments, are two cases in point. For extended discussion of theoretical developments in clinical linguistics, readers are referred to Cummings (2013) in the Further Reading section.

3.1. Phonetics

Phonetics is the study of the speech sounds of language in terms of how these sounds are produced (articulatory phonetics), how they are perceived (speech perception), and their physical properties (acoustic phonetics). This linguistic discipline is of fundamental importance to clinical linguistics. Speech sound production is a complex activity that depends on a number of anatomical structures and neuromuscular systems. Any condition, illness, or injury that compromises the development and function of these structures and systems can cause a phonetic disorder.

By way of illustration, consider the case of a child who is born with a cleft lip and palate (Sargent, 1997). This embryological malformation is associated with a range of phonetic deficits. Because palatal muscles that elevate the velum (soft palate) are defective, there may be partial or incomplete closure of the velopharyngeal port. This can result in the nasalization of vowels and other oral sounds as air escapes through the partially occluded port. In an effort to compensate for the lack of intra-oral air pressure during the articulation of speech sounds, children with cleft palate may shift the place of articulation of speech sounds backwards in the vocal tract. A preferred place of articulation where a complete blockage of the airstream can be achieved is the glottis. It is not uncommon, therefore, for children with cleft palate to substitute oral plosive sounds with the glottal stop [ʔ]. This can be seen in the following single-word productions of a 6-year-old girl called Rachel who was studied by Howard (1993). Rachel was born 11 weeks prematurely, with a central cleft of the hard and soft palates. She uses the glottal stop in place of all oral plosive sounds both in word-initial position and word-final position:

Clinical Linguistics

To understand this phonetic deficit, clinical linguists must have a sound understanding of articulatory phonetics. This includes knowledge of the structure and function of the velopharyngeal port and the implications of impaired functioning of this port for the production of speech sounds such as vowels and oral plosives. Knowledge of phonetics is also required to understand impairments of speech production in the dysarthrias (a group of developmental and acquired speech disorders related to neurological impairment) and in acquired speech disorders subsequent to trauma or surgical intervention (e.g., removal of part or all of the tongue in glossectomy).

3.2. Phonology

While phonetics is concerned with the characteristics of speech sounds, phonology examines the organization of speech sounds into systems. For clinical linguists, an important feature of the sound system of a language is the range of contrastive functions that it makes possible. Speakers who have a range of phonetic distinctions at their disposal can use these distinctions to signal differences between words. The contrastive function of phonetic distinctions is vital if speakers are to be intelligible to hearers. For example, the phonetic distinction between voiced and voiceless consonants in English allows a speaker to distinguish the word ‘pen’ [pɛn] from ‘Ben’ [bɛn] and the word ‘tin’ [tɪn] from ‘din’ [dɪn]. Similarly, the speaker who can use place of articulation contrastively is able to signal the difference between ‘cat’ [kæt] and ‘cap’ [kæp] and ‘take’ [teɪk] and ‘cake’ [keɪk].

To understand the impact of impaired phonology on communication, imagine a speaker who is unable to use voicing or place of articulation contrastively. Such a speaker would be unable to signal any difference between the words ‘chin’ [ʧɪn] and ‘gin’ [ʤɪn] (voicing) or between the words ‘like’ [laɪk] and ‘light’ [laɪt] (place of articulation). As might be expected, the intelligibility of such a speaker would be reduced in consequence. Because of the anatomical and physiological limitations imposed on her by her cleft palate, Rachel is unable to use place of articulation contrastively (see section 3.1, ‘Phonetics’). With all bilabial, alveolar, and velar plosives realized as a glottal stop, Rachel is unable to signal any difference between the words ‘tap’ and ‘cat,’ both of which are realized as [ʔæʔʰ]. This much-reduced system of sound contrasts has implications for her intelligibility. In Rachel’s case, a phonetic disorder caused by an anatomical malformation (cleft palate) has given rise to a phonological disorder. Phonological disorders may also occur in the absence of any anatomical defect or phonetic disorder. Consider the single-word productions below from a girl of 6.5 years called Katy, who was studied by Pascoe, Stackhouse, and Wells (2005):

Clinical Linguistics

In each of these productions, Katy has deleted either a singleton consonant or a consonant cluster in word-final position. In addition, she exhibits a number of other phonological processes in word-initial position. These processes include prevocalic voicing in ‘fish’; stopping, in ‘sink’; gliding, in ‘light’; and consonant cluster reduction in ‘queen.’ Moreover, these processes are an anomaly of Katy’s phonological system in the absence of any anatomical malformation and associated phonetic disorder. Although Rachel’s and Katy’s cases are somewhat different, they both illustrate the important role of phonology in clinical linguistics. The American Speech-Language-Hearing Association (ASHA) is the professional body that represents speech-language pathologists in the United States. Further information on phonological disorders in children is available from the American Speech-Language-Hearing Association.

3.3. Morphology

Morphology is the study of the internal structure of words and the principles and patterns that underlie this structure. Word structure is analyzed in terms of morphemes. These are the smallest meaningful units of a word. There are two main branches of morphology: inflectional morphology and word-formation. Both branches will be briefly described as they contribute important concepts to the study of language pathology. Inflectional morphology is the study of markers of grammatical categories, such as case, number, tense, and aspect. Inflectional morphemes attach to lexical stems and create new word-forms (rather than new words). In this way, the inflectional suffix –ing is added to the base form ‘eat’ to encode the progressive aspect (eating), while the addition of –s indicates agreement with a third-person singular subject (eats). Word-formation is the study of the rules and patterns that guide the formation of new words. Word-formation includes derivational morphology. New words are formed from the use of derivational morphemes in processes of prefixation (e.g., unkind, misunderstand) and suffixation (e.g., powerful, miserable). Compounding (e.g., country house), blending (e.g., infotainment from ‘information’ and ‘entertainment’), and clipping (e.g., flu from ‘influenza’) are further morphological processes that are studied within word-formation.

Morphological errors are commonly found in children and adults with language disorders. Inflectional morphology can be severely impaired in children with specific language impairment (SLI), a developmental language disorder of unknown etiology. For further information, see the website of the National Institute on Deafness and Other

Communication Disorders, for Specific Language Impairment. To illustrate these children’s difficulties with inflectional morphemes, consider the data from several children with SLI who were studied by Bliss et al. (1998), Colozzo, Gillam, Wood, Schnell, and Johnston (2011), Leonard, Deevy, Miller, Rauf, Charest, and Kurtz, (2003), and Schuele and Dykes (2005):

  1. (a) ‘It’s long ways to go.’

  2. (b) ‘If you just shoot it and it makes a basket not touching the rim or the the box, it’s still a points.’

  3. (c) ‘I flied and then I jumped down.’

  4. (d) ‘She hided right under the bushes.’

  5. (e) ‘Mimi help me blow out candles.’

  6. (f) ‘It go this way.’

These utterances reveal problems with both noun and verb morphology. In (a) and (b), the plural suffix –s has been incorrectly used on what should be two singular nouns. In (c) and (d), children with SLI have produced over-regularization errors. The regular past tense suffix –ed has been applied to the infinitive form of the verb when the verbs fly and hide have irregular past tense forms (flew and hid). Over-regularization errors also occur in the language of typically developing children. However, their presence in (c) and (d), which were produced by SLI children aged 9.3 years and 9.0 years, respectively, is a sign of morphological impairment. Children with SLI also omit obligatory inflectional suffixes. The child who produced the utterance in (e) fails to use the past tense suffix –ed for regular verbs, while the child who produced (f) omitted the third-person singular suffix –s.

Word-formation processes are also disrupted in language disorders. To illustrate the deviant use of one of these processes (blending), consider the following data from a study of confrontation naming in 15 adults with chronic schizophrenia that was conducted by Barr, Bilder, Goldberg, Kaplan, & Mukherjee (1989). The words to the left of the arrows are the target words, and the words to the right of the arrows are the subjects’ responses:

Clinical Linguistics

There is a recurring pattern in these responses. The first word in each pair—raft, nozzle, and octopus—is correctly produced. However, these correct responses are then carried over into the naming of the second word in each pair where they form a number of interesting blends with these words. The attempt to name ‘wreath’ results in rath, which is a blend of raft and wreath. The response to ‘noose’ is noosle, which is a blend of noose and nozzle. Finally, two blends are produced during the attempt to name ‘cactus.’ First, octatoos is produced, which is a blend of octopus and cactus. Second, captus is produced which is a blend of cactus and octopus. There is additional complexity in this second blend in that /p/ of captus is from ‘octopus’ while /t/ is from ‘cactus.’ Even as they reveal disruption in the morphology of language, the errors of these adults with schizophrenia are creative and fascinating.

3.4. Syntax

In no natural language of the world are words bundled into sentences in a random, unpredictable order. There is always some order to the occurrence of words in sentences. That order is examined in syntax. For example, adjectives that are used attributively in English appear in front of the nouns to which they relate. So the sentence Mary visited the ancient church is grammatical, while the sentence The doctor examined the man ill is not. If a cardinal numeral is added to the noun phrase, English word order requires that it stands in front of the adjective. So the sentence Mary visited two ancient churches is acceptable, while the sentence Mary visited ancient two churches is not. Languages vary in the word order that their sentences observe, a feature that is also of interest to linguists who study syntax. Although English word order prohibits sentences such as the doctor examined the man ill, in French sentences such as Pierre aime le chat noir (literal translation: Pierre likes the cat black) are grammatically acceptable. The study of word order within and across languages is of interest to syntacticians, both for what it can reveal about the organizing principles of individual languages and of the human language faculty itself.

Sentence structure can be severely impaired in developmental and acquired language disorders. Knowledge of grammatical concepts, and how to apply these concepts to a characterization of disordered language, is thus of vital importance to clinical linguists. Children and adults with genetic syndromes, such as Down syndrome (Genetic and Rare Diseases Information Center, 2015) and fragile X syndrome (Genetic and Rare Diseases Information Center, 2016a), can experience intellectual disability of varying degrees of severity. In the presence of even mild to moderate intellectual disability, the acquisition of the grammar of language may be delayed or deviant. Children with intellectual disability may be unable to use and understand grammatical constructions that are used and understood by their chronological age peers. To illustrate the grammatical immaturities of expressive language in children with intellectual disability, consider the following conversational exchange between an examiner (E) and a child (JB) who was studied by McCardle and Wilson (1993). JB has FG syndrome and agenesis of the corpus callosum. FG syndrome is an X-linked recessive disorder that is found predominantly in males (Genetic and Rare Diseases Information Center, 2016b). Intellectual disability is one of its clinical features. JB was 5 years 7 months old at the time this extract was recorded:

E: Tell me about your dog.

JB: It go woof woof. I have a doggie, yep.

E: What’s your doggie’s name?

JB: Spot. Spot doggie puppy dog. They go pee-pee. Go pee-pee (pointing to the floor). Smell (holding nose, laughing). I go fight doggie (kicking the air). Puppy dog go bite.

JB’s grammatical repertoire is quite limited for a child of 5.7 years. For the most part, his expressive language is restricted to the use of nouns (e.g., doggie, puppy) and verbs (e.g., smell, fight). There are no adjectives or adverbs in JB’s expressive language. With the exception of the occasional use of pronouns (e.g., I, they) and only one instance of the indefinite article ‘a,’ function words are also completely lacking. So there are no prepositions, conjunctions, and auxiliary verbs, all of which may be expected to be present in the speech of a child of JB’s age. In addition to a limited range of grammatical categories, JB’s expressive language exhibits a further significant feature. He omits the inflectional suffix in ‘It go woof woof.’ The third-person singular, present tense verb ending –s is acquired by 5.7 years in typically developing children. In an effort to compensate for his limited expressive language, JB makes extensive use of gesture, pointing, and actions. In sum, there is substantial evidence of grammatical delay in JB’s expressive language, a delay that clinical linguists must look to syntax or grammar to characterize.

Clinical linguists must also have knowledge of syntax in order to characterize the linguistic impairment known as agrammatism in aphasia. For information on aphasia, visit The National Institute on Deafness and Other Communication Disorders (NIDCD) website. The agrammatic speaker produces utterances that have reduced syntactic structure. In most cases, only content words (nouns, verbs, adjectives) are retained. The loss of function words such as prepositions, articles, and conjunctions confers a telegrammatic quality on spoken output. The following example of agrammatic speech from an adult with aphasia is taken from Bastiaanse and Prins (2014). This adult is able to produce proper nouns (e.g., Amsterdam, Mary), common nouns (e.g., car, bike), adjectives (e.g., beautiful, nice), and main or lexical verbs (e.g., walk, talking). However, function words such as pronouns, conjunctions, prepositions, and articles are used infrequently, mostly on single occasions. The retention of content words still allows the speaker to be informative to some degree, even as spoken communication is particularly effortful:

Amsterdam … and eh … beautiful … eh … I … nice … walk [Okay. Where?] Where? Eh … Amsterdam [Are you walking around the city?] No bike or no eh … eh … car eh … shopping … and eh … eh call and eh … first eh … eh … cup of coffee … eh … Mary and eh … talking a bit.

(Bastiaanse and Prins, 2014, p. 230).

As these examples illustrate, impairments of sentence structure can adversely affect communication for a range of children and adults. In all cases, a sound working knowledge of the syntax or grammar of language is required in order to characterize and treat these impairments.

3.5 Semantics

The study of word and sentence meaning in semantics is an important linguistic discipline for clinical linguists. Semantic concepts and theoretical approaches can be used extensively to characterize semantic impairments in children and adults with language disorders. Componential analysis is a case in point. According to componential analysts, words are not the smallest units of meaning. Rather, smaller components of meaning known as semantic components or primitives come together in different combinations to give the meanings of words. For example, the meaning of the word mother can be captured by the components [FEMALE] and [PARENT], while man requires a combination of three components: [ADULT] [MALE] [HUMAN]. Words can enter into a range of sense relations with other words in language. These so-called lexical relations include different types of opposition in antonymy (e.g., hot and cold are gradable antonyms, while employer and employee are converse antonyms), the relation of inclusion in hyponymy (e.g., parrot and eagle are hyponyms of bird), and the part-whole relation of meronymy (e.g., chapter and index are meronyms of book). Semanticists are also concerned to characterize the different semantic roles associated with the argument structure of verbs. For example, the verb ‘give’ in the sentence Mary gives the book to John has three arguments that correspond with the semantic or thematic roles of agent (Mary), recipient (John), and patient (the book).

Each of these aspects of semantics can be used to characterize semantic impairments in children and adults with language disorders. Adults with aphasia, dementia, or cerebral infections (e.g., herpes simplex encephalitis) often exhibit naming and comprehension deficits. At least some of these deficits appear to involve impairment of specific categories in semantic memory. These categories are distinguished by whether or not their members exhibit properties such as abstract and concrete, or animate and inanimate. Properties of this type have the status of semantic components or primitives. In an early study, Warrington and Shallice (1984) examined category-specific semantic impairments in four patients who had made a partial recovery from herpes simplex encephalitis. All four patients exhibited greater difficulty identifying animate things and food than inanimate objects. For one of these patients, the comprehension of abstract words was significantly superior to the comprehension of concrete words. Examples of the responses of one of the four patients (J.B.R.) to inanimate object words and living things are shown below:

  • Inanimate objects:
  • Tent: temporary outhouse, living home
  • Briefcase: small case used by students to carry papers
  • Compass: tools for telling direction you are going
  • Torch:hand-held light
  • Dustbin: bin for putting rubbish in

  • Living things:
  • Parrot: don’t know
  • Daffodil: plant
  • Snail: an insect animal
  • Eel: not well
  • Ostrich: unusual

While J.B.R.’s descriptions of the inanimate objects were accurate and detailed, his descriptions of animate things were little more than the superordinate term of the category to which the word belonged (‘plant’ for daffodil and ‘insect animal’ for snail). Another patient (S.B.Y.) gave exact definitions of abstract words, even as his definitions of concrete words were vague and inaccurate:

  • Abstract words:
  • Debate: discussion between people, open discussions between groups.
  • Malice: to show bad will against somebody.
  • Deceive: to let people down, give them the wrong ideas and wrong impression.
  • Caution: to be careful how you do something.

  • Concrete words:
  • Ink: food—you put on top of food you are eating—a liquid.
  • Frog: an animal—not trained.
  • Cabbage: use for eating, material it’s usually made from an animal.
  • Tobacco: one of your foods you eat.

Lexical or sense relations provide a rich descriptive framework in which to capture the semantic errors of adults with aphasia. Buckingham and Rekart (1979) examined the semantic paraphasic errors of a 74-year-old, right-handed woman (‘JT’) who developed Wernicke’s aphasia following a left parietal cerebrovascular accident. Several of this woman’s errors, both in structured tasks (e.g., picture identification) and conversation, involved substitutions of semantically related words. A number of these substitutions were based on antonymy, with the target word substituted by its antonym (the target word in each case is enclosed in parentheses). In the first two examples, JT is talking about her son who lives in Florida:

‘Well the first one lived in—uh—down on the north (south).’

‘They don’t come down (up) …. He’ll come up after it’s colder ….’

‘They’re too big (little)! They’re too big! They gotta make bigger for my feet … my shoes are little aren’t big enough.’

‘It wasn’t cold (hot) for me. I had to close the [wɪnər].’

A further lexical relation—the part-whole relation of meronymy—explains at least one of the semantic paraphasic errors produced by a 66-year-old male with fluent anomic aphasia who was studied by Conroy, Sage, and Ralph (2009). During a description of the cookie theft picture in the Boston Diagnostic Aphasia Examination (Goodglass, Kaplan, and Barresi, 2001), the client described the woman in the picture as by the kitchen when she is actually next to the sink (‘sink’ is a meronym of ‘kitchen’). This client’s anomia is further evident in the use of the non-specific lexeme ‘stuff’ for water and the superordinate term ‘seat’ for stool:

‘The woman is by the kitchen, stuff is running over onto the floor. She is …, she cannot …, the young fellow has got up to the cupboard and is about to fall off the seat. The young girl is after some from this lad.’

Semantic roles may be impaired in children and adults with language disorders. Adults with agrammatic aphasia often omit obligatory semantic roles in their production of verbs. Prinz (1980) reported the case of a 59-year-old man with Broca’s aphasia who, when required to request a pen to sign his name on a piece of paper, only uttered ‘need (gestures writing).’ Two obligatory semantic roles—agent (‘I’) and patient (‘a pen’)—were omitted by this man. Thompson (2003) found that there was a hierarchy of difficulty in verb production by people with agrammatic aphasia, with one-place verbs (e.g., Jack smiles) produced more frequently during narrative tasks than two-place verbs (e.g., Molly hit the table) and three-place verbs (e.g., Sally gave her laptop to Sam). A much-reduced range of semantic roles can thus be expressed by these clients.

3.6. Pragmatics

Pragmatics is defined as the study of language meaning in context or, in some definitions, non-literal meaning or implied (intended) meaning. Pragmatic concepts such as speech act, implicature, deixis and presupposition are essential to the characterization of disordered language. Pragmatists are interested in the range of uses to which utterances can be put beyond merely describing states of affairs in the world. Utterances may be used to make promises (e.g., I will be at the party tonight), convey warnings (e.g., The river has burst its banks) and threats (e.g., A wise man would not give evidence in court), and make apologies (e.g., I’m so sorry I was late). These different speech acts can be performed felicitously and infelicitously (only someone with religious authority, for example, can felicitously utter I baptize this child Mark Jones), and may be used directly or indirectly (the utterance It’s warm in here can be used to make an indirect request for someone to turn down the heating). The implicated meanings of a speaker’s utterances (so-called implicatures) are also central to pragmatics. They include the conventional implicature in the utterance Even Bill passed the exam (it was not expected that Bill would pass the exam) and the scalar implicature in the utterance Mary bought some of the books on the reading list (Mary did not buy all the books on the reading list). Implicatures are one of the most extensively investigated pragmatic concepts in clinical linguistics.

No pragmatic concept exemplifies the relation of language to context better than deixis. Deictic expressions, which include personal pronouns (e.g., I, you), verbs (e.g., take, bring), adverbs (e.g., here, there), and adjectives (e.g., last, next), have as their referents individuals and entities within the wider temporal, spatial and discourse context of an utterance. In this way, the speaker who utters I would love to live here during a visit to Paris is using personal deixis (‘I’ refers to the speaker) and spatial deixis (‘here’ refers to Paris). Expressions can have multiple deictic functions such as when the demonstrative pronoun ‘this’ is used for spatial deixis in I walk home this way, temporal deixis in Rose leaves for Moscow this week and discourse deixis in Your argument in this section is weak. Finally, pragmatists are also interested in how speakers represent background knowledge and beliefs in the presuppositions of utterances. The speaker who utters It was the teenager who vandalized the bus shelter presupposes that his hearer knows that someone vandalized the bus shelter. Presuppositions can be triggered by a range of lexical items and syntactic constructions (the cleft construction It was … is the presupposition trigger in the above utterance). Unlike entailment, presuppositions can also survive under negation (the utterances Joan managed to climb the wall and Joan did not manage to climb the wall both presuppose that Joan tried to climb the wall).

Pragmatic concepts may be impaired in children and adults with language disorders. For verbal children with autism (National Institute of Mental Health, 2016a), there may be a reduced number and range of speech acts. In the following exchange between a therapist (T) and a child (P) with autism, the child’s speech acts are largely limited to comments on his own activity. Meanwhile, the therapist uses a range of speech acts in an attempt to elicit a wider speech act repertoire from the child. However, each of the therapist’s turns, which include a question, a statement and two commands, fail to elicit any engagement from the child:

T: What are you going to do with that car now?

P: I like my car (pushing it on the floor)

T: Look. I’ve got one like that.

P: In here it goes (pushing car into garage)

T: Don’t forget to shut the doors.

P: Find the man now (looking about)            From Crystal and Varley (1998, p. 161)

The recovery of the implicatures of utterances is a complex pragmatic skill that draws on a range of cognitive and linguistic abilities. This skill is often impaired in adults with schizophrenia (National Institute of Mental Health, 2016b). Colle, Angeleri, Vallana, Sacco, Bara, and Bosco (2013) examined the ability of adults with schizophrenia to derive the intended meaning of utterances. The subjects in this study were shown a videotaped scenario involving two people, Robert and Paola. It’s Robert’s birthday, and Paola gives him a gift saying “Happy birthday!” Robert unwraps the gift and discovers an awful tie. With an annoyed expression he says “Thanks, really, I needed one of those.” The responses of one adult with schizophrenia to the test questions in the study are shown below:

What did Robert say? He liked the tie.

In your opinion, did Robert like the tie? Kind of.

Why? He made a perplexed expression.

Robert’s annoyed expression indicates that what he saying is false (i.e., Robert’s utterance does not adhere to the maxim of quality). Hearers with intact pragmatic language skills assume in such a case that Robert is still adhering to the cooperative principle. This assumption of cooperation leads hearers to infer that it is Robert’s intention to be sarcastic. The adult with schizophrenia who produced the above responses is unable to recover the sarcastic intent that motivated Robert’s utterance.

The use of presupposition to represent knowledge shared by speakers and hearers may be impaired in children and adults with language disorders, particularly pragmatic disorders. McTear (1985) examined a 10-year-old boy with pragmatic disorder. In one exchange with this child (C), an adult (A) introduces a communication task. The task involves games that are unfamiliar to the child. To this extent, the child’s utterance ‘they are indeed’ contains a false presupposition—the child cannot possibly know that the games are easy when he is unfamiliar with them. Alongside this pragmatic impairment, however, there is evidence of appropriate use and understanding of deictic expressions. The child displays no difficulty in establishing the referents of the pronouns ‘you’ and ‘me’ in the adult’s first turn, and is able to use ‘they’ to refer to the games:

A: Now do you want to see if you can play some games with me?

C: Yes.

A: They’re very easy games um (1.0).

C: They are indeed.

A: Well, we’ll see.

3.7. Discourse

Extended extracts of spoken and written language are the focus of the study of discourse. Such extracts may be found in newspapers, blogs, debates, and speeches. Discourse may be monological (e.g., narrative, speech) or dialogical (e.g., conversation, debate) in nature. Some forms of discourse involve scripted or pre-planned language (e.g., a formal speech), while other forms are spontaneous and unfold in real time (e.g., conversation between friends). Regardless of the type of discourse, discourse analysts are concerned to examine the internal structure of extended extracts of language. This structure manifests itself in various ways. One way is the use of cohesive devices to join sentences to each other. Cohesion can take many forms and includes anaphoric reference (e.g., Mary bought the blue dress. It was very expensive), substitution (e.g., Fran wants the red hat. It is the one in the window), and ellipsis (e.g., Who would like a latte? I would). Spoken and written discourse that lacks cohesive devices appears disjointed and cannot be easily understood. But even discourse that is cohesive in nature may not be understood if it is not also coherent. Discourse coherence can be variously defined. In general, it captures the extent to which a spoken or written text holds together and makes sense as a whole. The connectedness of a discourse’s various components or elements depends, in part, on cohesion. However, it also depends on whether relevant information is presented, and whether that information is presented in temporal order and with consideration of causal relations between events.

Topic management is a key aspect of any coherent discourse. It is a complex discourse skill that draws on a wide range of cognitive and linguistic resources. The selection of a topic of conversation, for example, requires that a speaker attribute mental states to the mind of a hearer, a cognitive capacity known as theory of mind. This is because the topic must appeal to the interests and preferences (i.e., mental states) of hearers if it is to have any purpose or value in a conversational exchange. Once a topic that is of interest to hearers has been selected, a speaker must be able to integrate it skillfully into a conversation. Clumsy topic introduction may be registered by hearers as an abrupt shift in topic. Having introduced a topic, the speaker must be able to develop it in ways that are of interest and relevance to all conversational participants. A topic of limited relevance and interest will be rapidly relinquished in favor of another. Finally, even topics of high interest and relevance cannot be extended indefinitely. There comes a point where topic termination must occur. Like topic introduction, there are more and less skilled ways of terminating a topic so that the appearance of an abrupt change of topic does not arise.

Discourse impairments are commonly found in children and adults with language disorders. Several such impairments occur in the conversational exchange below between a teacher (T) and a child called Adam (A) who was studied by Peets (2009). Adam has attention deficit hyperactivity disorder or ADHD (National Institute of Mental Health, 2016c). He is explaining snow tubing to his teacher and some of his peers:

A: I went to my cousin’s house and when I went to my cousin’s house that was later when I when I we went back home for um from snow tubing.

T: Can you tell us about snow tubing?

A: Snow tubing is is freaky.

T: Freaky. Tell us what it’s like. What do you do?

A: They uh they have a machine that will they have a hooks that will pull you back up and then you have eight tickets you give one of them to (th)em then you got hold onto a rope they have like a little round thing and then you go they put the put the hook inside and then and then it pulls you back up and then you slide down they put they maybe the if you want to stay straight you tell my parents from up there if you want a spin they he spins you.

Cohesion is an area of difficulty for Adam. This is evident in his impaired use of anaphoric reference. On several occasions, Adam produces pronouns such as ‘they’ and ‘he’ in the absence of prior referents. His explanation is difficult to follow for this reason. But it is also difficult to follow on grounds of poor coherence. Adam presents information in the wrong temporal order. This can be seen at the start of the extract when he says he went to his cousin’s house. Later in the same turn, he has to explain that he went to his cousin’s house after he came back home from snow tubing. The inevitable confusion that this account of events will create for Adam’s listeners could be avoided if he related events in the temporal order in which they occurred.

Children and adults with language disorders can also struggle with topic management. In the following conversational exchange taken from Kennedy (2000), a 63-year-old man (‘PT’) with right-hemisphere brain damage is talking to a 48-year-old woman (‘DT’) with no neurological impairment. The conversation is in its termination phase.

  1. 1 DT: We’ll, I wish we had more time, I’d love to hear more about your travels.

  2. 2 PT: Yeah, I’d like to have a drink. (alcohol had been brought up previously)

  3. 3 DT: But I think __________ is expecting us and I think she has something that she wants you to work on—so, it’s been nice chatting with you, we will have to talk again.

  4. 4 PT: It’s been nice talking with you, ________, very nice. (pause) Outside of Yugoslavia, there is a place I’d like to go to and that is Australia.

  5. 5 DT: Really, they are supposed to be beautiful—lots to see.

  6. 6 PT: But, we only have one lifetime.

  7. 7 DT: Yeah, but, it’s seems like you’ve made a good whack at it.

  8. 8 PT: Yes, I have.

  9. 9 DT: Well, I hope that you are not going to stay at ___________ too much longer and you can get back …

  10. 10 PT: I hope not, within a month, I’m supposed to go with Jim to Jamaica.

  11. 11 DT: Oh.

  12. 12 PT: Looking for a lady or whatever …

  13. 13 DT: (laughs) Good luck.

On two occasions, DT attempts to terminate the conversation. However, on each occasion, PT introduces a new topic. This first occurs in turn 4 when, after a pause, PT starts to talk about how he would like to visit Australia. In turn 9, DT again tries to terminate the conversation only for PT, in turn 10, to start talking about a trip to Jamaica with Jim. The effect of each new topic introduction is to forestall closure and extend the conversation beyond its natural point of termination.

Further Reading

Ball, M. J., Perkins, M. R., Müller, N., & Howard, S. (Eds.), (2010). The handbook of clinical linguistics. Oxford: Blackwell.Find this resource:

    Crystal, D. (2001). Clinical linguistics. In M. Aronoff & J. Rees-Miller (Eds.), The handbook of linguistics (pp. 673–682). Oxford: Blackwell.Find this resource:

      Crystal, D. (2013). Clinical linguistics: Conversational reflections. Clinical Linguistics & Phonetics, 27(4), 236–243.Find this resource:

        Cummings, L. (2008). Clinical linguistics. Edinburgh, U.K.: Edinburgh University Press.Find this resource:

          Cummings, L. (2013). Clinical linguistics: State of the art. International Journal of Language Studies, 7(3), 1–32.Find this resource:

            Cummings, L. (Ed.), (2014). Cambridge handbook of communication disorders. Cambridge, U.K.: Cambridge University Press.Find this resource:

              Fabbro, F. (Ed.), (1999). Concise encyclopedia of language pathology. Oxford: Elsevier Science.Find this resource:

                Fava, E. (Ed.), (2002). Clinical linguistics: Theory and applications in speech pathology and therapy. Amsterdam and Philadelphia: John Benjamins.Find this resource:

                  Perkins, M. R. (2011). Clinical linguistics: Its past, present, and future. Clinical Linguistics & Phonetics, 25(11–12), 922–927.Find this resource:


                    Barr, W. B., Bilder, R. M., Goldberg, E., Kaplan, E., & Mukherjee, S. (1989). The neuropsychology of schizophrenic speech. Journal of Communication Disorders, 22(5), 327–349.Find this resource:

                      Bastiaanse, R., & Prins, R. S. (2014). Aphasia. In L. Cummings (Ed.), Cambridge handbook of communication disorders (pp. 224–246). Cambridge, U.K.: Cambridge University Press.Find this resource:

                        Bliss, L. S., McCabe, A., & Miranda, A. E. (1998). Narrative assessment profile: Discourse analysis for school-age children. Journal of Communication Disorders, 31(4), 347–363.Find this resource:

                          Buckingham, H. W., & Rekart, D. M. (1979). Semantic paraphasia. Journal of Communication Disorders, 12(3), 197–209.Find this resource:

                            Colle, L., Angeleri, R., Vallana, M., Sacco, K., Bara, B. G., & Bosco, F. M. (2013). Understanding the communicative impairments in schizophrenia: A preliminary study. Journal of Communication Disorders, 46(3), 294–308.Find this resource:

                              Colozzo, P., Gillam, R. B., Wood, M., Schnell, R. D., & Johnston, J. R. (2011). Content and form in the narratives of children with specific language impairment. Journal of Speech, Language, and Hearing Research, 54(6), 1609–1627.Find this resource:

                                Conroy, P., Sage, K., & Ralph, M. L. (2009). Improved vocabulary production after naming therapy in aphasia: Can gains in picture naming generalize to connected speech? International Journal of Language & Communication Disorders 44 (6), 1036–1062.Find this resource:

                                  Crystal, D., & Varley, R. (1998). Introduction to language pathology (4th ed.). London, U.K.: Whurr.Find this resource:

                                    Cummings, L. (2011). Pragmatic disorders and their social impact. Pragmatics and Society, 2(1), 17–36.Find this resource:

                                      Cummings, L. (2014). Pragmatic disorders. Dordrecht, Netherlands: Springer.Find this resource:

                                        Genetic and Rare Diseases Information Center. (2015). Down syndrome. Bethesda, MD: U.S. Department of Health & Human Services, National Institutes of Health.

                                        Genetic and Rare Diseases Information Center. (2016a). Fragile X syndrome. Bethesda, MD: U.S. Department of Health & Human Services, National Institutes of Health.

                                        Genetic and Rare Diseases Information Center. (2016b). FG syndrome. Bethesda, MD: U.S. Department of Health & Human Services, National Institutes of Health.

                                        Goodglass, H., Kaplan, E. & Barresi, B. (2001). Boston diagnostic aphasia examination (3d ed.). Baltimore, MD: Lippincott, Williams, & Wilkins.Find this resource:

                                          Howard, S. J. (1993). Articulatory constraints on a phonological system: A case study of cleft palate speech. Clinical Linguistics & Phonetics, 7(4), 299–317.Find this resource:

                                            Kennedy, M. R. T. (2000). Topic scenes in conversations with adults with right-hemisphere brain damage. American Journal of Speech-Language Pathology, 9(1), 72–86.Find this resource:

                                              Leonard, L. B., Deevy, P., Miller, C. A., Rauf, L., Charest, M., & Kurtz, R. (2003). Surface forms and grammatical functions: Past tense and passive participle use by children with specific language impairment. Journal of Speech, Language, and Hearing Research, 46(1), 43–55.Find this resource:

                                                McCardle, P., & Wilson, B. (1993). Language and development in FG syndrome with callosal agenesis. Journal of Communication Disorders, 26(2), 83–100.Find this resource:

                                                  McTear, M. F. (1985). Pragmatic disorders: A case study of conversational disability. British Journal of Disorders of Communication, 20(2), 129–142.Find this resource:

                                                    National Institute of Mental Health (2016a). Autism spectrum disorder. Bethesda, MD: National Institutes of Health.

                                                    National Institute of Mental Health (2016b). Schizophrenia. Bethesda, MD: National Institutes of Health.

                                                    National Institute of Mental Health (2016c). Attention deficit hyperactivity disorder. Bethesda, MD: National Institutes of Health.

                                                    National Institute on Deafness and Other Communication Disorders (2015). How do we hear? Bethesda, MD: National Institutes of Health.

                                                    Pascoe, M., Stackhouse, J., & Wells, B. (2005). Phonological therapy within a psycholinguistic framework: Promoting change in a child with persisting speech difficulties. International Journal of Language & Communication Disorders, 40(2), 189–220.Find this resource:

                                                      Peets, K. F. (2009). Profiles of dysfluency and errors in classroom discourse among children with language impairment. Journal of Communication Disorders, 42(2), 136–154.Find this resource:

                                                        Prinz, P. M. (1980). A note on requesting strategies in adult aphasics. Journal of Communication Disorders, 13(1), 65–73.Find this resource:

                                                          Sargent, L. A. (1997). Craniofacial surgery: Clefts of the lip and palate. Chattanooga: Tennessee Craniofacial Center.

                                                          Schuele, C. M., & Dykes, J. C. (2005). Complex syntax acquisition: A longitudinal case study of a child with specific language impairment. Clinical Linguistics & Phonetics, 19(4), 295–318.Find this resource:

                                                            Thompson, C. K. (2003). Unaccusative verb production in agrammatic aphasia: The argument structure complexity hypothesis. Journal of Neurolinguistics, 16(2–3), 151–167.Find this resource:

                                                              Warrington, E. K., & Shallice, T. (1984). Category-specific semantic impairments. Brain, 107(3), 829–854.Find this resource: