|Tariana is the only Arawak language spoken in the linguistic area of the Vaupés river basin in the territory of the Upper Rio Negro in northwestern Brazil. All the other languages belong to the East Tucano subgroup of the Tucano family. The main feature of the Vaupés area is its obligatory multilingualism, dictated by the principles of linguistic exogamy (one has to marry someone who speaks a different language). There is a strong inhibition against 'language-mixing', viewed in terms of lexical loans. As the result of a long-term interaction, Tariana combines a few features inherited from Proto-Arawak, with those diffused from East Tucano.