On the Underspecification of Functional Categories in Early Grammars

Children's early linguistic productions are typically characterized by the variable or null use of grammatical function items. These morphologically impoverished productions have frequently been interpreted as evidence for the rudimentary nature of early child grammars. Drawing on evidence from both English and Sesotho, this paper provides a sketch of a Metrical Model of Production that accounts for much of the reported omission and variability in children's early production of functional categories. The paper concludes that variable morphological 'underspecification' is largely a reflection of children's incomplete productive capacities rather than a lack of grammatical competence. 1.0 Introduction It has long been observed that children tend to omit closed class grammatical function items in early speech (Bloom, 1970; Brown, 1973). These observations have taken on new importance with recent developments in linguistic theory, where determiners, complementizers, subject-verb agreement and auxiliaries are all classified as functional (as opposed to lexical) categories, heading their own projections (Abney, 1987; Fukui and Speas, 1985; Chomsky, 1988). Indeed, functional categories are seen to encapsulate many of the critical aspects of syntactic structure itself. That early stages of language acquisition apparently lack these grammatical function items has led some researchers to propose that children's early grammars are syntactically impoverished, initially being composed of only a VP (e.g. Guilfoyle and Noonan, 1989; Lebeaux, 1988; Radford, 1990). Others suggest that children may fluctuate between two competing structural representations, one with functional projections, the other without (e.g. Lebeaux, 1988). However, still others argue that children's early productions represent an incomplete picture of children's actual grammatical competence (e.g. Lee, Lust, and Whitman, 1990; Whitman, Lee and Lust, 1991; Demuth, 1992a). Although each of these different points of * I thank audiences at the Cornell University Symposium on Syntactic Theory and First Language Acquisition, the University of Connecticut at Storrs, and the 17th Annual Conference on Language Development, as well as two anonymous reviewers, for comments and discussion.