Theories of how second languages are learned have been approached from a variety of perspectives: sociolinguistic, educational, neurolinguistic, psycholinguistic, linguistic. Each of these approaches brings to second language studies its goals, its data collection methods, and its analytic tools. Because of this diversity, it is often difficult for researchers from different traditions to communicate with one another or to fully appreciate the significance of the questions being addressed.

The purpose of this book is to elucidate these issues from a linguistic point of view, focusing in particular on the potential relationship between second language acquisition and linguistic theory. Thus, the papers represent a range of views on this relationship and describe a variety of linguistic theories. However, they all agree on the importance of grounding second language acquisition research within a theoretical framework that will illuminate the nature of language.

There are many ways of characterizing the relationship between a theory of language and a theory of second language acquisition. In the ideal situation, this relationship is, or should be, bidirectional. The theory will guide and constrain the hypotheses that the researcher is willing to entertain and test in considering both the course of language development and the ultimate knowledge to be attained. Conversely, particular language acquisition studies will provide empirical evidence for or against specific theoretical models. We hope that this book will clarify and hence shed light on these issues.