In this new book Liliane Haegeman presents an account of sentential negation within a Government and Binding framework. Building on the work of Klima and Lasnik, Haegeman demonstrates the parallelism between negative sentences and interrogative sentences, and gives a unified analysis in terms of a well-formedness condition on syntactic representations: the AFFECT criterion, instantiated as the WH criterion in interrogative sentences and as the NEG criterion in negative sentences. It is shown that in the same way that in many languages the WH criterion gives rise to WH movement, the NEG criterion may also give rise to NEG movement. This book will be of interest to all those working on theoretical syntax, particularly of the Germanic and Romance languages.