Specificity in the development of language structure

The nature of children's productive structures can be investigated via two types of structural error which are manifest in their surface data: the overextension of a very general adult rule to a context from which it is excluded, and the introduction of a novel rule in a specific context. Examples of these two types of errors are shown, on the one hand, to undermine theories which treat language development largely as a process of projecting and testing innately specified hypotheses; on the other hand, they provide support for more recent theories which conceive of abstract linguistic structure as the outcome of a process relating specifically acquired items and combinations of items. The implications of this conception for the goals and tasks of developmental psycholinguistics are explored.This paper is based on research undertaken for the Ph.D degree under the supervision of Dr. N. V. Smith, University College, London, and with the financial support of the Social Science Research Council of Great Britain.