This book covers the range of ways in which corpora can be gainfully employed in sociolinguistic enquiry, critically discussing corpus analytical procedures such as frequencies, collocations, dispersions, keywords, key keywords and concordances. Aimed at undergraduate and postgraduate students of sociolinguistics, or corpus linguists who wish to use corpora to study social phenomena, it examines how corpora can be used to investigate synchronic variation and diachronic change by referring to a number of classic corpus-based studies as well as the author's original research.