This course introduces students to a basic fact about language in general and English in particular. This fact is that English is not a single monolithic linguistic system. Like other living languages English exhibits variation at all levels of structure, from phonology to discourse. The course outlines and elaborates on the parameters by which language use shows obvious differences. The basic parameters are: region, social class, ethnic group, sex, age, situation, and mode of use in a variety of professional fields-(registers).