This article aims to contribute (1) new data on verbal -s by systematically examining its behavior in Devon English (DE), a variety spoken in southwest England, and (2) a broader historical and cross-dialectal perspective for understanding the origin and function of verbal -s in nonstandard varieties of English in North America. We focus on the linguistic contexts of its occurrence from the diachronic and synchronic literature. The results show that verbal -s is conditioned by phonological, syntactic, semantic, and lexical factors. These include the few variable constraints on verbal -s attested throughout the evolution of verbal -s in the history of the English language. Moreover, DE exhibits patterns of verbal -s variability that have previously been associated with African American Vernacular English (AAVE). The detailed nature of these linguistic correspondences—not only in frequency of the features examined, but most importantly in the details of an entire set of internal linguistic factors conditioning them—reveal that verbal -s is a linguistic feature of AAVE that originated in British dialects.