The morphosyntactic development of Atlantic creoles, including Krio, an English-based creole in Sierra Leone, is a highly debated issue, with the controversy centering on the extent of the influence of the properties of substrate West African languages, if any, on the development of Krio morphosyntax. Contrary to proposals that creoles (including Krio) tend to exhibit basic, universal, simplistic, and transparent grammar, this paper presents evidence of substratal influence on the morphosyntactic properties of Krio. The properties of three morphosyntactic structures—focused constructions, verb serialization, and complementation—are examined and evidence is provided for an intricate and productive system of morphosyntactic operations that sometimes generate structures of a regional rather than a universal orientation. In addition, these are linguistically marked structures that are extremely difficult to account for under proposed universal unmarked principles of grammar as currently stipulated.