Two terms commonly heard today in language educators' public and professional lives are globalization and the social turn. Both of these phenomena have had a significant impact on the field of sociolinguistics. The first has resulted in greater movement of individuals within countries and across borders motivating some to acquire new languages and identities, and leading many sociolinguists to investigate the hybridity of current language use. Globalization has also resulted in more attention being devoted to the relationship between language and power and critical approaches to language use and language learning. The second, the social turn in the field of applied linguistics, has resulted in far more attention being given to the social aspect of language use, so that today there are a growing number of studies on the relationship between such things as language and identity, style and styling, and language and gender. One of the major purposes of this book is to provide an up-to-date overview of the effect of these two phenomena on language use and the development of the field of sociolinguistics.

We believe that this text, addressed to experienced and novice language educators, is necessary today given changes in the global situation and continuing evolution in the field of sociolinguistics. The following factors of the political, social and academic world today are contributing to the need for a sociolinguistic text addressed to language educators. First, throughout the world, multicultural and multilingual classrooms are becoming the rule rather than the exception. Hence, on a daily basis, language professionals are witnessing the results of languages in contact where codeswitching and codemixing are common and where students bring to the classroom various ways of using language. Second, growing research in the field of sociolinguistics has led to new areas of specialization, for example critical language awareness, multimodality literacies and language socialization, along with more long-standing areas such as language planning, multilingualism and cross-cultural variation in language use, each with its own view of how language and society interact.