Variability is characteristic of any living language. This volume approaches the 'life cycle' of linguistic variability in English using data sources that range from electronic corpora to the internet. In the spirit of the 1968 Weinreich, Labov and Herzog classic, the fifteen contributions divide into three sections, each highlighting different stages in the dynamics of English across time and space. They show, first, how increase in variability can be initiated by processes that give rise to new patterns of discourse, which can ultimately crystallize into new grammatical elements. The next phase is the spread of linguistic features and patterns of discourse, both new and well established, through the social and regional varieties of English. The final phase in this ebb and flow of linguistic variability consists of processes promoting some variable features over others across registers and regional and social varieties, thus resulting in reduced variation and increased linguistic homogeneity.