Accessing functional categories in Sesotho: interactions at the morpho-syntax interface

Language acquisition studies have long noted that early acquisition patterns differ in important ways from those of adult speech. Specifically, early child language is full of what have generally been called ‘open class items’ (e.g. nouns, verbs), but relatively lacking in ‘closed class items’ (e.g. determiners, complementizers, etc.). Furthermore, early child language differs from adult language in that it seems to lack some types of movement (e.g. subject-aux inversion in English, verb movement in German). Drawing on recent developments in linguistic theory, where the organization of grammar is centered around Functional Categories such as DET, INFL, COMP and their projections (e.g. Abney, 1987; Fukui and Speas, 1985), it has been proposed that it is precisely these functional elements themselves that may be lacking from early child grammars (e.g. Radford, 1990; Guilfoyle and Noonan, 1988; see also Lebeaux, 1988). This would account for both the early lack of dosed class items, and the early lack of movement to these functional, or head, positions.