This book is a pedagogical rather than a scientific grammar. Specifically, it seeks to describe those aspects of transformational grammar that, in my opinion, have the greatest relevance for teachers and prospective teachers of English. It is designed so that it may be used as a text, by departments of English and schools of education, but I believe it can also be used independently by teachers who have completed their formal education. In short, it is my hope that teachers will learn something valuable about the nature of English from this text and that this knowledge will improve their teaching and help their students.