The proposed research will shed new light on a debate within Bantu, the largest language family in Africa and a recent offshoot of Niger-Congo, the world’s largest phylum. Many non-Bantu Niger-Congo languages have an analytical morphosyntactic profile, while a great majority of Bantu languages have an agglutinative profile, which was also reconstructed for Proto-Bantu. The controversy revolves around which of these two profiles is innovative. It actually boils down to whether today’s morphology is yesterday’s syntax or the other way around. Scholars involved in the debate have used a top-down approach and argued for opposite directions of change based on (virtually) the same random selection of distantly-related Niger-Congo languages, without relying on the Comparative Method. This project aims at a paradigm shift by using a bottom-up methodology to test these two hypotheses against a suitable empirical ground for morphosyntactic reconstruction. The West-Coastal Bantu (WCB) branch of the Bantu family is a uniquely suited test case for at least three reasons: (i) it includes analytical and agglutinative languages; (ii) recent fieldwork shows morphosyntactic reanalysis processes that are rather exceptional in Bantu; and (iii) WCB has a relatively shallow time depth (± 2500 years), i.e. it is easier to control for the effect of cyclicity in morphosyntactic change. The project’s main outcome will be the reconstruction of the Proto-WCB morphosyntactic profile and its evolutions.