This paper concerns bilingualism in the Chulumani sector of Sud Yungas province, department of La Paz, in Bolivia. Chulumani is the capital of a very mountainous province, which drops rapidly from peaks of more than 5,000 metres above sea level, through crumpled subtropical valleys to the lowland forests. The town itself stands at about 1,700 metres above sea level. Before the agrarian reform carried out between 1953 and 1964, the region was divided between free peasant communities and haciendas operated by labour tenure; since then it has been dominated by peasant smallholders (Leons 1967, 1979). The community where I worked was a hacienda which had been founded in 1560 and reformed (that is, the land distributed to the tenants) in 1964; I will refer to it as ‘Takipata’. The principal activity is agriculture 1 , and the principal crop is coca. Coca has a multitude of religious and social uses in the Andean world, and since about 1971 it has provided the raw material for a huge export boom, although it has to be emphasised that cocaine is quite distinct from coca and the vast majority of peasant coca farmers have nothing to do with it. This boom collapsed in 1986, but coca continues to maintain a relatively buoyant local economy, evidenced by the presence of numerous young men and women in the towns and countryside. It is highly labour-intensive, and Sud Yungas is a recipient of labour from higher regions of Bolivia, especially male labour for the less specialised agricultural activities.