Conjugation Class

Abstract

Conjugation classes have been defined as the set of all forms of a verb that spell out all possible morphosyntactic categories of person, number, tense, aspect, mood, and/or other additional categories that the language expresses in verbs. Theme vowels instantiate conjugation classes as purely morphological markers; that is, they determine the verb’s morphophonological surface shape but not its syntactic or semantic properties. They typically split the vocabulary items of the category verb into groups that spellout morphosyntactic and morphosemantic feature specifications with the same inflectional affixes. The bond between verbs and their conjugational marking is idiosyncratic, and cannot be established on semantic, syntactic, or phonological grounds, although there have been serious attempts at finding a systematic correlation. The existence of theme vowels and arbitrary conjugation classes has been taken by lexicalist theories as empirical evidence to argue against syntactic approaches to word formation and are used as one of the main arguments for the autonomy of morphology. They further raise questions on the nature of basic morphological notions such as stems or paradigms and serve as a good empirical ground for theories of allomorphy and syncretism, or to test psycholinguistic and neurolinguistic theories of productivity, full decomposition, and storage. Conjugations and their instantiation via theme vowels may also be a challenge for theories of first language acquisition and the learning of morphological categories devoid of any semantic meaning or syntactic alignment that extend to second language acquisition as well. Thus, analyzing their nature, their representation, and their place in grammar is crucial as the approach to these units can have profound effects on linguistic theory and the architecture of grammar.