This book combines ideas about the architecture of grammar and language acquisition, processing, and change to explain why languages show regular patterns when there is so much irregularity in their use and so much complexity when there is such regularity in linguistic phenomena. Peter Culicover argues that the structure of language can be understood and explained in terms of two kinds of complexity: firstly that of the correspondence between form and meaning; secondly in the real-time processes involved in the construction of meanings in linguistic expressions. Mainstream generative theory is based on inherent linguistic competence and on the regularities within and across languages, with the exceptional aspects of any language frequently put to one side. But a language's irregular and unique features offer, the author argues, fundamental insights into both the nature of language and the way it is produced and understood. Peter Culicover's new book offers a pertinent and original contribution to key current debates in linguistic theory. It will interest scholars and advanced students of linguists of all theoretical persuasions.