This textbook, aimed primarily at beginning undergraduates studying for degrees in English, provides an introduction to a range of sociolinguistic theories and the insights they provide for a greater understanding of varieties of English, past and present. Drawing on both qualitative and quantitative approaches to sociolinguistic variation, the book provides a systematic overview of such topics as: * 'English' as a social and as a linguistic concept* The relationship between regional and social dialectology, and their application to the study of English* English historical sociolinguistics, from Old English to late Modern English* Sociolinguistics and change in English* Outcomes of contact involving varieties of English* English and language planning* English, sociolinguistics and linguistic theory.The book contains data drawn from studies of English as it is used around the world. Throughout, there is an emphasis on facilitating a deeper understanding of linguistic variation in English and the soc