The authors emphasise the variation that exists in the use of spoken English and the implications of this variation, arguing that language ability could be more accurately assessed with attention to speakers' total communicative competence. This new edition of the book has been revised to include recent developments in the field. It emphasises the increasing interest in English language teaching leading to the recommendations of the Kingman and Cox reports and the National Curriculum. This makes it an indispensable book for educationalists, teachers and linguists.