The psychological reality of children's grammars and its relation to grammatical theory

It is proposed that there are currently two branches of the study of children's language - Child Language, and Language Acquisition. The goals of each one are distinct, and each is sceptical of the work of the other. Here, the goals of each one are described, and a reconciliation is attempted. It is argued that this is possible if each acknowledges (1) the need to construct a theory of language acquisition, and (2) the role of acquisition data in grammatical theory. Language acquisition data will play a role if we allow theories of grammar to make predictions about children's language. Specific assumptions are proposed that make this possible.