This accessible new textbook provides a clear introduction to sociolinguistics, the study of why we speak the way we do, and the social factors that influence our linguistic decisions. Based on the notion of 'choice' - that as speakers we select from the options open to us - it provides a solid theoretical framework to deal with the most fascinating characteristic of language: its variability and diversity. Topics covered include dialects, gender and age specific speech forms, professional jargons, diglossia, bilingualism, code-switching, pidgin languages, and language planning, all of which are unified by the common theme that speakers, by making choices, create their language. Drawing on linguistic variation from a wide range of societies and their languages, this is set to become a key text for all students of sociolinguistics, and will be welcomed by anyone interested in the complex interaction between language and society.