ABSTRACT This project will investigate a number of current theoretical issues in the acquisition of language, through the detailed experimental study of the development of one module of linguistic competence, the anaphoric phenomena which are the subject of binding theory, in English and Chinese. The project will chart many important aspects of this development. The English data will be collected in the United States, and the Chinese data in Taiwan, in collaboration with colleagues there. Among the topics to be considered will be (1) the interaction between the formulation of Chomsky's "Principle B" with regard to bound variables and referential pronouns, and the child's knowledge of the principle; (2) the apparent lack of long-distance binding in the Chinese of the young child; (3) the possibility of explaining anomalous acquisition phenomena by the Subset Principle and a parameterized theory with independent parameters, on the one hand, versus a richly interrelated developmental theory on the other hand; (4) the explanation of long-distance binding via LF movement of the reflexive, and the slow development of long-distance binding; and (5) the development of non-canonical patterns such as chain-binding and binding of adjuncts. %%% The study of language acquisition by children has moved in the direction of seeking much more comprehensive and more formalized theoretical modeling, informed by developments in linguistic theory. This project reflects that trend, and furthers it. It also responds to the increasing emphasis on cross-linguistic study of language acquisition, in the attempt to discover patterns of development which are general to human beings, not just to those speaking a particular language.