This paper discusses the usage of done in ‘she’s done send the photographs’ as a marker of completive aspect in the variety of English spoken on the island of Tristan da Cunha in the South Atlantic Ocean. The article outlines the various positions scholars have taken with reference to the diachronic status of ‘completive done’ and discusses the structural properties of the (aux)+ done V construction in Tristan da Cunha English (TdCE). The aim of the analysis is twofold: first, to present a structural and semantic analysis of done as a marker of perfective aspect, with the aim of investigating if TdCE done has taken a different syntactic and semantic trajectory vis-à-vis its use in other varieties; and second, to explain the sociohistorical origins of done in this variety of South Atlantic English. The comparative analysis shows that particularly the structural properties of TdCE done differ significantly from those of other varieties; the diachronic examination shows the complexity of determining the contributions of transplant varieties, mixing of colonial varieties of English, and independent developments that originate in creolisation and/or language contact.