The Bantu languages comprise a group of some 500-650 languages spoken across much of Eastern, Central and Southern Africa. While the Bantu languages share a number of broad typological structural similarities, they also exhibit a high degree of micro-variation – that is small-scale differences found between closely related languages or varieties. This makes the language family the ideal lens through which to examine processes of language contact and change, as well as the constraints operative on these. This talk explores the dynamics of structural change, drawing on data from language ecologies in East African which have a high presence of Bantu languages. The talk highlights the ways in which comparative evidence and investigations can improve our understanding of both present-day and historical language dynamics.