This document discusses language variation between social classes. It provides examples of Cockney English and Black English that show differences in pronunciation patterns across classes. It also summarizes research by William Labov on social stratification of language use in New York City, and his finding that upper-class department store customers pronounced /r/ more strongly. Finally, it mentions British linguist Alan Ross' terms "U English" and "non-U English" to describe vocabulary differences that reflected class anxieties in 1950s Britain.