This book examines the extent to which the underlying linguistic competence of learners or speakers of a second language (L2) is constrained by the same universal principles that govern natural language in general. It is presupposed that there is an innately given Universal Grammar (UG), which constrains first language (L1) grammars, placing limits on the kinds of hypotheses that L1 acquirers entertain as to the nature of the language that they are acquiring. Assuming the correctness of this general approach, the question arises as to whether UG constrains grammars in non-primary language acquisition as well. This book will present and discuss research which investigates whether or not interlanguage grammars can be characterized in terms of principles and parameters of UG, and which explores the nature of interlanguage competence during the course of L2 acquisition, from the initial state onwards. It is hoped that the book will provide sufficient background for the reader to understand current research conducted within the framework of UG and L2 acquisition.

The generative perspective on L2 acquisition is sometimes dismissed because it has a rather circumscribed goal, namely to describe and explain the nature of interlanguage competence, defined in a technical and limited sense. Researchers whose work is discussed in this book do not seek to provide an all encompassing theory of L2 acquisition, or to account the role of performance factors, psychological processes and mechanisms, sociolinguistic variables, etc.