Portraying foundation issues, recent advances and current debates, presenting familiar or classic information in new ways and supplementing the familiar with fresh examples from a wide range of languages and social settings, this book clearly explains the patterns and systems that underlie language variation in use, as well as the ways in which alternations between different language varieties index personal style, social power and national identity. The book provides an up-to-date overview of sociolinguistics, reflecting changes in the global situation and the continuing evolution of the field and its relevance to language.