Mundurukú

Munduruku is a Tupi language spoken by 10,000 people in the Tapajós River basin in north central Brazil.

Gomes (2006) points out that Munduruku is one of the languages of the Tupian family and constitutes, together with Kuruaya, the Munduruku linguistic branch [...] The Portuguese language has made significant inroads among the Munduruku but most of the women and children are monolingual. Some loss of the Munduruku language is occurring among those who live in the area of the Madeira River and on the outskirts of the towns next to the Tapajós River; however the situation is not as bad as it seems, as even here the language of the majority is Munduruku and bilingualism arises only after Munduruku has already been acquired (around 10 years of age), usually as a result of learning Portuguese at school.

Those who live in the villages of the Tapajós River valley speak only Munduruku, even in the presence of non-indigenous people. There are elementary schools in almost all villages, and courses promoted by the Brazilian government have turned over education to the Mundurukú, who are starting to take control of their own formal education."

From Wikipedia · Munduruku language · CC BY-SA 4.0