Regional variation in written American English The first study of its kind Regional Variation in Written American English takes a corpus based approach to map over a hundred grammatical alternation variables across the United States. A multivariate spatial analysis of these maps shows that grammatical alternation variables follow a relatively small number of common regional patterns in American English which can be explained based on both linguistic and extra linguistic factors. Based on this rigorous analysis of extensive data Grieve identifies five primary modern American dialect regions demonstrating that regional variation is far more pervasive and complex in natural language than is generally assumed. The wealth of maps and data and the groundbreaking implications of this volume make it essential reading for students and researchers in linguistics English language geography computer science sociology and communication studies