The languages of Australia, generally recognized as falling into two groups, Pama-Nyungan and non-Pama-Nyungan, are remarkable for their phonological and morphological homogeneity. All Australian languages exhibit a range of suffixation for grammatical and derivational categories, typically with a high index of agglutination, along with widespread patterns of compounding and reduplication, in the latter case, often of unusual types. In some Pama-Nyungan languages, case suffixation forms complex constructions indexing multiple levels of relations within the clause and across clauses, including agreement of nouns with verbs for erstwhile cases which have developed into tense-aspect-modality systems. Non-Pama-Nyungan languages tend to have more elaborate verbal structures, including such features as incorporation of nouns and adverbs, cross-referencing of multiple participants, valence-changing morphology, and systems of noun class/gender agreement across the clause, typically of four to five classes. Many languages from both subgroups have complex predicate formations, which typically inhabit a region between phrasal and compound status. Finite verbs commonly inflect for a smallish number of tense-aspect-mood categories and can often be classified into a number of conjugation classes. Nouns by contrast rarely (if ever) inflect in patterns characteristic of declension classes in European languages. Words appear to be largely right-headed, based on the evidence of noun-adjective compounds. Gender/noun class systems in some languages have been co-opted by the case system to mark case relations, and in others to realize derivational meanings such as association or part-whole relations. Pronominal agreement systems in both PN and NPN languages can reach Baroque levels of complexity in incorporating distinctions based on social categories such as sibling, social category membership (such as moeity) and kinship. Bound pronominal agreement with a single argument is exceedingly rare: if there is a verbal or clitic agreement system, it almost always agrees with at least two arguments.