Since it first appeared more than fifteen years ago, Ronald Wardhaugh's An Introduction to Sociolinguistics has been an immensely popular textbook for courses in sociolinguistics and the sociology of language. Organized in four parts – Languages and Communities, Inherent Variety, Words at Work, and Understanding and Intervening – the book offers an accessible, comprehensive introduction to sociolinguistics. Topics explored include language, dialects, pidgins and creoles, codes, bilingualism, speech communities, variation, and change. The book also covers words and culture, ethnographies, solidarity and politeness, talk and action, gender, disadvantage, and planning. In the fourth edition, the text, further reading sections, exercises, and references have been revised and updated to reflect new developments in the field. In particular, the coverage of gender, disadvantage, and planning has been considerably revised and extended.