In this important and pioneering book, Frederick Newmeyer takes on the question of language variety. He considers why some language types are impossible and why some grammatical features are more common than others. The task of trying to explain typological variation among languages has been mainly undertaken by functionally-oriented linguists. Generative grammarians entering the field of typology in the 1980s put forward the idea that cross-linguistic differences could be explained by linguistic parameters within Universal Grammar, whose operation might vary from language to language. Unfortunately, this way of looking at variation turned out to be much less successful than had been hoped for. Professor Newmeyer's alternative to parameters combines leading ideas from functionalist and formalist approaches which in the past have been considered incompatible. He throws fresh light on language typology and variation, and provides new insights into the principles of Universal Grammar. The book is written in a clear, readable style and will be readily understood by anyone with a couple of years' study of linguistics. It will interest a wide range of scholars and students of language, including typologists, historical linguists, and theorists of every shade.