The research reported is an investigation into the early acquisition of grammar by three children from the age of approximately 19 months. Nonlinguistic information from situational and behavioral context was used to infer the semantic intent of utterances in order to analyze the development of linguistic expression. Previous psycholinguistic studies of child language had described utterances in terms of the orderly distribution with which words occurred in juxtaposition. In this study, by making judgments of semantic intent structure of utterances so that conclusions could be drawn about the child's knowledge of semantic-syntactic relationship in the derivation of sentences. For example, when the child said “Mommy sock” and Mommy was putting the child's sock on the child, it was clear that a different semantic interpretation was intended than when the child said “Mommy sock” and picked up Mommy's sock. The syntactic components of generative transformational grammars were proposed for those samples of the children's language in which mean length of utterance was less than 1.5 morphemes.
For the psychologist, the book provides added insight into the relative development of syntactic expression and underlying cognitive function. It was clear, for example, that the two did not develop hand in hand. For the linguist, the book provides additional evidence for the growing conclusion that child language is not incoherent. There is strong evidence presented to demonstrate the extent (and limitations) of the child's knowledge of basic grammatical relations in the earliest two-word utterances. For the speech pathologist concerned with language disorders in children, the evidence presented and the resulting conclusions should provide important hypotheses for application in treatment.
One of the major contributions that the book will make to the literature on child language is the presentation of a large body of data in support of the conclusions that have been drawn. There is an extensive catalog of the children's earliest two-ward utterances, negative sentences, and syntactic and single-word lexicons. The material presented on negation is of particular importance. This evidence should prove invaluable to other researches in the field.