In the last 30 years, linguists have built a considerable and highly sophisticated body of work on generative grammar. Today the field is more active than ever before. Introduction to the Theory of Grammarmakes available to teachers and students of syntax a comprehensive critical review of the main results of present day grammatical theory and shows how they were achieved. It presents the central questions, shows how and why they were asked, what the answers were, and how these have led to new questions. Part I discusses the way in which the overly rich, descriptive rule systems of the fifties and sixties have gradually been replaced by simpler, more constrained rule systems. Much of the work originally done by stipulations in the rules themselves has been taken over by general, universal principles which govern the form and functioning of these rules and the properties of their inputs and outputs. The establishment of such a theory of principles is the main topic of Part II. Part III addresses the problem of how semantics fits into grammar and elaborates a conception of how the syntactic properties of logical representations can be integrated into the overall theory of grammar. The rules and principles of grammar developed in these parts account for grammatical phenomena in an essentially modular way, and this system of modules, which constitutes the study of grammar today, is established in Part IV. An Epilogue describes such current developments as generalized binding, phrase structure, small clauses, tree geometry and NP-structure. Henk van Riemsdijk is full professor in the Department of Language and Literature, Tilburg University, Holland. Edwin Williams is professor of linguistics, University of Massachusetts, Amherst. Introduction to the Theory of Grammaris twelfth in the series Current Studies in Linguistics.