Introduction

In the generative linguistics literature, there are numerous findings that support the view that an innate linguistic capacity (Universal Grammar (UG), Chomsky, 1965, 1981, etc.) plays a role in guiding first language acquisition by human beings. However, not much is known about whether UG is active from the beginning of development or whether it matures at a certain point in development. Thus, whether UG remains constant in child development remains to be investigated. To put this in the terminology of psycholinguistics, there is an issue of whether continuity (Pinker, 1984; Hyams, 1986) holds for UG in language development or whether some part of UG undergoes maturation in accordance with a genetically determined developmental schedule (Borer & Wexler, 1987, 1992). If continuity holds, UG remains constant in language development, and no part of UG undergoes maturation. As the null hypothesis, continuity seems to have a conceptual advantage over maturation. However, empirical assessment is necessary in arguing for either continuity or maturation. In this chapter, we discuss two syntactic constructions in Japanese, negative clauses and direct passives, paying special attention to their innate properties. For each construction, we evaluate data from child Japanese in order to determine empirically whether continuity in language development holds for the innate properties under consideration.

To assess the status of UG in language development, special attention is paid to children's grammatical errors. Children's errors deviate from the grammar of the target language to be acquired.