This thesis first provides a grammar sketch of Teke-Kukuya which is a Bantu language spoken in the Republic of Congo, covering the topics on its segmental phonology and prosodic system, noun classes and noun phrases, verbal morphology and TAM conjugations, as well as some syntactic issues based on newly collected data. The second part of the thesis investigates the interaction between syntax and information structure in this language. The author discusses word order variation and expressions of information structure with particular interests in a dedicated immediate-before-verb (IBV) focus position in this language. Since the IBV focus construction shares many grammatical properties with clefts, both segmentally and tonally, the author makes the hypothesis that diachronically the IBV focus strategy originates from a basic cleft, and it has been grammaticalised towards a monoclausal focus construction. The thesis also gives a synchronic analysis on the structural representation of the IBV focus construction, discussing the subject agreement asymmetry in subject/non-subject relatives and the associated class 1 subject marking alternation in the IBV focus construction.