Grammaticalization refers to the change whereby lexical terms and constructions serve grammatical functions in certain linguistic contexts and, once grammaticalized, continue to develop new grammatical functions. Paul Hopper and Elizabeth Traugott synthesize research from several areas of linguistics including historical linguistics, discourse analysis, and pragmatics in this revised introduction to the subject. Data are drawn from many languages including Ewe, Finnish, French, Hindi, Hittite, Japanese, Malay, and especially English. The book includes substantial updates on theoretical and methodological issues that have arisen in the decade since the first edition, as well as a significantly expanded bibliography. Particular attention is paid to recent debates over directionality in change and the role of grammaticalization in creolization.