This volume is an introduction to the two most influential versions of syntactic theory to have emerged during the last decade - Government and Binding Theory evolving from Chomsky's generative grammar, and the two latest forms of phrase structure grammar, Generalized Phrase Structure Grammar and Head-Driven Phrase Structure Grammar. The German version of the book (the original was published by Edward Arnold in 1991 as ""Syntactic Theory - A Unified Approach"") is greatly expanded in comparison to the English original in that it discusses the various problems of syntactic theory not only with reference to English but also to German. This gives the reader an interesting opportunity for comparisons between the structural features of the two languages. It also transpires that in some instances the differences in structure between the two languages call for modifications to the theoretical approach.