The Acquisition of Swahili Verbal Morphology

Recently, much attention has focused on the so-called Root Infinitive(RI) phenomenon, where children in languages such as German use infinitival verbs in root context, seemingly optionally. English has been argued to be an RI language (Wexler 1994), though English speaking children use bare stems instead of infinitives. Languages such as Italian, however, have been shown not to exhibit RIs in early child language. I present results from a study of Swahili, a Bantu language with rich agglutinative morphology. Swahili is an SVO language in which the verbal clause has the following order of morphemes in an affirmative indicative sentence: Subject Agreement – Tense/Aspect – (Object Agreement) – Verb Root – (derivational suffixes) – Mood Vowel. If we assume that the linear order of morphemes is a reflection of the hierarchical order of heads (Baker’s (1985) Mirror Principle), then the morphology of Swahili allows us to test various theories of the dropping of functional morphemes. The speech of four Swahili speaking children ranging in age from 1;8 to 3;1 was recorded in Kenya, transcribed in the CHAT format and coded. The results show that Swahili children do not produce RIs, but do omit Agr and T/A markers. Thus the verb may surface with a Person agreement marker alone, a T/A marker alone, or neither Person nor T/A. In the latter case the verb appears as a bare stem, analogous to what we find in English. These results are discussed in the light of various theoretical analyses of RIs, specifically the Metrical Omission Model (Gerken, 1991), the Small Clause Hypothesis (Radford 1986; Radford 1990), Rizzi’s (1994) Truncation hypothesis, Wexler’s (1994) underspecification of tense theory, Hoekstra & Hyams’ (1998) underspecification of number theory, and Schütze & Wexler’s (1996) ATOM model. The basic clause typology is found to be most compatible with ATOM, although ATOM fails to account for many of the details in the data.