This paper explores the complementation phenomenon in Leteh. The discussion is done within the framework of Basic Linguistic Theory (Dixon 1997), and further appeals to the theory of grammaticalization to explain the multiple functions of Leteh complementizers. Leteh is a South Guan (Kwa, Niger-Congo) language spoken in Larteh, in the southeastern part of Ghana. In Leteh, complement clauses mainly function as sentential objects of main clauses. Complement clauses in Leteh are signaled by three complementizers: ye, n., and b.., which combine with complement-taking verbs from four semantic classes to produce the types of complement clauses that operate in the language. There are co-occurrence restrictions between complementizers and complement-taking verbs. For instance, when the complement-taking verb occurring in the main clause is an utterance verb, the complementizer that initiates the complement clause must be ye. Finally, the paper demonstrates that complementizers could have a verbal origin, contrary to assertions in the literature (Noonan 2007: 57).