The Aikanã and Kwaza languages are genetic isolates, which means that they are apparently not related to any of the world’s languages or linguistic families. There are notable similarities between the Aikanã and Kwaza languages that are also shared with Kanoê (the other isolate of southeastern Rondônia). Although there is no compelling evidence that they are genetically related to one another, the possibility of a long-distance genetic relationship cannot be excluded. At any rate, their lexicons are almost completely different, and those etymological correspondences that can be found are usually so close that they must be the result of borrowing. Areal diffusion may explain part of the similarities between these languages since these language groups are known to have married and forged alliances across ethno-linguistic lines.