We sketch a project that marries probabilistic grammar research to scholarship on World Englishes, thus synthesizing two previously rather disjoint lines of research into one unifying project with a coherent focus. This synthesis is hoped to advance usage-based theoretical linguistics by adopting a large-scale comparative and sociolinguistically responsible perspective on grammatical variation. To highlight the descriptive and theoretical benefits of the approach, we present case studies of three syntactic alternations (the particle placement, genitive, and dative alternations) in four varieties of English (British, Canadian, Indian, and Singapore), as represented in the International Corpus of English. We report that the varieties studied share a core probabilistic grammar which is, however, subject to indigenization at various degrees of subtlety, depending on the abstractness of the syntactic patterns studied.