During recent years interest in language varieties has steadily increased. Rather than simply describing homogenous language systems, linguists have begun to study language heterogeneity. This study attempts to bring the two approaches together by exploring the notion of a varieties grammar, by discussing its implications, its problems and possibilities, both from a theoretical and practical point of view. Special importance is attributed to the definition of varieties as «typolects» and of grammar as «holistic». Evaluative data are derived from a first-hand account of contemporary varieties of California English.