The linguistic area of the Vaupés
Languages of three unrelated families are spoken in the basin of the Vaupés river (Brazil and Colombia): East-Tucano, North Arawak, and Makú. This area is characterized by mostly one-way areal diffusion from East-Tucano into the other languages (see Sorensen 1967; Aikhenvald 1996, 1999b).
In particular, East-Tucano languages and Tariana display a striking number of structural similarities due to areal diffusion, mostly one-way, from East Tucano to Tariana. ‘Direct’ diffusion (i.e. lexical loans: Heath 1978) is almost non-existent, due to the inhibition concerning ‘language mixing’ viewed in terms of lexical interference and the borrowing of the phonological shape of morphemes (see Aikhenvald 1999b).
Other North Arawak languages spoken in the region of the Upper Rio Negro but outside the Vaupés area are Baniwa of Içana, Bare and Warekena of Xié.
All speakers of Tariana are bilingual in at least one East-Tucano language (most often, Tucano). Tariana shows a considerable degree of structural isomorphism with East-Tucano languages — in phonology, grammatical categories, agreement patterns and semantics — though this isomorphism is not complete.
Tariana retains a considerable number of grammatical and lexical morphemes of Arawak origin and a predominantly suffixing word structure, with a limited number of prefixes, typical of the Arawak family. Tucano languages, in contrast, are entirely suffixing.
Another important characteristic of the Vaupés area (at least on the Brazilian side) is the growing endangerment of all languages other than Tucano.
Tariana is one of the most endangered of these languages (see Aikhenvald 1996). It is not spoken by children; even fluent speakers of the middle generation speak Tucano between themselves.10 Language obsolescence has resulted in the loss of quite a few morphemes and categories of North Arawak origin. There are massive loan translations and grammatical calques from Tucano.
As I have shown elsewhere (Aikhenvald 1996), borrowed grammatical categories in Tariana verbs include evidentials fused with tense, a switch reference system, and a complicated system of moods and aspects. These are absent from other North Arawak languages of the region.
