Corpus linguistics is a research approach to investigate the patterns of language use empirically, based on analysis of large collections of natural texts. While corpus-based analysis has had relatively little influence on theoretical linguistics, it has revolutionized the study of language variation and what speakers and writers actually do with the lexical and grammatical resources of a language. Corpus-based research employs the research methods of quantitative and qualitative social science to investigate language use patterns empirically. This four-volume collection is organized around linguistic research questions that can be investigated from a corpus perspective and includes amongst others studies of individual words, comparisons of supposedly synonymous words, studies of grammatical variation, and sociolinguistic studies of dialects, registers, styles, and world varieties. Corpus-based analysis has also proven to be important for the study of historical change.