This is a most interesting book and offers lots of new insights into language variation and change, the role of new technologies in the evolution of language use, new speech 'communities' of multilingual speakers and also further explorations of the relationship between SLA and sociolinguistics which add to those already in existence. In addition, there are interesting implications for language teaching and learning. * Vera Regan, University College Dublin, Ireland * Mercedes Durham's important new book contributes to our understanding of sociolinguistic variation in a multilingual context in general and to the role of English as a lingua franca in Switzerland in particular. Through rigorous analysis, the author shows how non-native speakers of English acquire considerable sociolinguistic competence. The findings reported here suggest that our ideas of sociolinguistic competence need to be redefined as English gains wider currency as a global language. * Robert Bayley, University of California, Davis, USA *