Parameterization in labeling: Evidence from child language

Abstract This paper examines very early child grammars from the minimalist perspective. It discusses the well-known erroneous strings very young children produce such as Root Infinitives in English and their Japanese counterparts, preverbal object sentences in English, and sentences without Case markers in Japanese. The main question to be addressed is whether those sentences children produce are labeled, and if so, how the labeling takes place. Assuming that ϕ-feature agreement and suffixal Case markers play crucial roles for labeling in English and Japanese respectively (Chomsky 2013; Saito 2016), I consider two possibilities. One is that children are equipped with those almost from the outset although they are not phonetically realized. This means that even the erroneous strings children produced are properly labeled. The other is that those strings are not labeled in the adult way and that children at the relevant stage are still in the process of figuring out how the {XP, YP} structure is labeled in their respective languages. I argue that the latter is a viable possibility, given the parameterization in the labeling mechanism, and receives support from the child data as well. This conclusion implies that a main part of the acquisition of syntax is for a child to discover how her/his target language labels the {XP, YP} structure.