In several Bantu languages in the regions where Kikongo and Lingala are spoken, we encounter sentences where the word person can appear after the subject of a canonical SVO sentence, resulting in a focused interpretation of the subject. Synchronically, we analyze this as a monoclausal focus construction with moto person as a focus marker. Diachronically, we argue, the construction derives from a biclausal cleft, where moto functioned as the head noun of the relative clause. This is a crosslinguistically rare but plausible development. The different languages studied in this paper show variation in the properties indicative of the status of the moto construction , which reflects the different stages of grammaticalization. Finally, we show how contact-induced grammaticalization is a likely factor in the development of moto as a focus marker.