This books provides an introduction to three contemporary syntactic theories, Government-Binding Theory, Generalized Phrase Structure Grammar, and Lexical-Functional Grammar. In successive chapters, Sells lucidly presents and illustrates the fundamental apsects of each theory. In an introductory chapter he describes the basic syntactic concepts and assumptions shared by each theory; in the postscript, Thomas Wasow provides a more general overview of the different perspectives of these three approaches.