ABSTRACT
This chapter argues for a rich interpretation of children's early language production. It is concerned with variation in how languages package morphosyntactic information in words. One source of evidence is in studies of language pathology, where the contrast of performance for the vocabulary classes has been a matter of interest to researchers for many years. Psycholinguistic research, a model of language production, and syntactic theory converge on a framework that relies on two distinctions that figure in children's earliest utterances: the distinction between heads and nonheads, and the distinction between lexical and functional categories. The chapter also argues that in languages where one word has tags agreeing with other parts of its host sentence, it is easy to support a rich interpretation of children's first utterances. Evidence from other areas of psycholinguistics, showing that both the closed/open class distinction and the head/nonhead distinction figure in important ways into language processing theory, is also crucial.
