ABSTRACT
What is Second Language Acquisition? Second language acquisition research focuses on the developing knowledge and use of a language by children and adults who already know at least one other language. This field of research has both theoretical and practical importance. The theoretical importance is related to our understanding of how language is represented in the mind and whether there is a difference between the way language is acquired and processed and the way other kinds of information are acquired and processed. The practical importance arises from the assumption that an understanding of how languages are learned will lead to more effective teaching practices. In a broader context, a knowledge of second language acquisition may help educational policy makers set more realistic goals for programmes for both foreign language courses and the learning of the majority language by minority language children and adults. This chapter begins with a discussion of some of the linguistic and psychological
theories which have informed second language acquisition research. This is followed by a review of research findings on learners’ developing knowledge and use of their second language (L2), including a discussion of how previously learned languages affect that development. The final section examines the role of instruction in L2 development.
