This book quickly established itself as a classic treatment of its subject on first publication in 1985. Nearly ten years on it has undergone revision, drawing not only on fresh research and new understandings but also on the detailed reaction of readers and reviewers to the original edition. A comprehensive index has also been added. The book presents an outline of the grammar of modern English in the framework of systemic-functional linguistic theory and serves as an introduction to functional theory in general, which can be used for describing any language in its own terms. The description of English presented here has been widely used in a number of applied linguistics contexts, particularly artificial intelligence and language education, both second language and mother tongue, but also in literary stylistics and other fields requiring a rich interpretation of the text.