Blending is a type of word formation in which two or more words are merged into one so that the blended constituents are either clipped, or partially overlap. An example of a typical blend is brunch, in which the beginning of the word breakfast is joined with the ending of the word lunch. In many cases such as motel (motor + hotel) or blizzaster (blizzard + disaster) the constituents of a blend overlap at segments that are phonologically or graphically identical. In some blends, both constituents retain their form as a result of overlap, for example, stoption (stop + option). These examples illustrate only a handful of the variety of forms blends may take; more exotic examples include formations like Thankshallowistmas (Thanksgiving + Halloween + Christmas). The visual and audial amalgamation in blends is reflected on the semantic level. It is common to form blends meaning a combination or a product of two objects or phenomena, such as an animal breed (e.g., zorse, a breed of zebra and horse), an interlanguage variety (e.g., franglais, which is a French blend of français and anglais meaning a mixture of French and English languages), or other type of mix (e.g., a shress is a type of clothes having features of both a shirt and a dress). Blending as a word formation process can be regarded as a subtype of compounding because, like compounds, blends are formed of two (or sometimes more) content words and semantically either are hyponyms of one of their constituents, or exhibit some kind of paradigmatic relationships between the constituents. In contrast to compounds, however, the formation of blends is restricted by a number of phonological constraints given that the resulting formation is a single word. In particular, blends tend to be of the same length as the longest of their constituent words, and to preserve the main stress of one of their constituents. Certain regularities are also observed in terms of ordering of the words in a blend (e.g., shorter first, more frequent first), and in the position of the switch point, that is, where one blended word is cut off and switched to another (typically at the syllable boundary or at the onset/rime boundary). The regularities of blend formation can be related to the recognizability of the blended words.
Derivational morphology is a type of word formation that creates new lexemes, either by changing syntactic category or by adding substantial new meaning (or both) to a free or bound base. Derivation may be contrasted with inflection on the one hand or with compounding on the other. The distinctions between derivation and inflection and between derivation and compounding, however, are not always clear-cut. New words may be derived by a variety of formal means including affixation, reduplication, internal modification of various sorts, subtraction, and conversion. Affixation is best attested cross-linguistically, especially prefixation and suffixation. Reduplication is also widely found, with various internal changes like ablaut and root and pattern derivation less common. Derived words may fit into a number of semantic categories. For nouns, event and result, personal and participant, collective and abstract noun are frequent. For verbs, causative and applicative categories are well-attested, as are relational and qualitative derivations for adjectives. Languages frequently also have ways of deriving negatives, relational words, and evaluatives. Most languages have derivation of some sort, although there are languages that rely more heavily on compounding than on derivation to build their lexical stock. A number of topics have dominated the theoretical literature on derivation, including productivity (the extent to which new words can be created with a given affix or morphological process), the principles that determine the ordering of affixes, and the place of derivational morphology with respect to other components of the grammar. The study of derivation has also been important in a number of psycholinguistic debates concerning the perception and production of language.