The Boro–Garo languages form four groups: Boro, Garo, Koch and Deori.
Boro–Garo languages were historically very widespread throughout the Brahmaputra Valley and in what are now the northern parts of Bangladesh,[2] and it is speculated that the proto-Boro-Garo language was the lingua franca of the Brahmaputra valley before it was replaced by Assamese, to which it has made major contributions.
There is some flexibility in the order of the arguments, but a nominative–accusative distinction is marked with post-nominal clitics.
[7] This would account for the highly reduced morphology of Boro–Garo, with what morphology is present mostly being regular, loosely bound, and with transparent etymology, typical signs of recent origin.
Jacquesson (2017:112)[2] classifies the Boro-Garo languages as follows, and recognizes three major branches (Western, Central, and Eastern).