Some loss of the Munduruku language is occurring among those who live in the area of the Madeira River and in 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 of is Munduruku, and bilingualism only takes place after Munduruku has already been acquired (around 10 years of age), usually as a result of learning Portuguese at school.
There is a loss of the Munduruku language among those living in areas near the Madeira River and outside towns close to the Tapajós River; however, this issue isn't as severe as it might seem. Despite this, most people still speak Munduruku, and bilingualism develops only after acquiring the language (usually around 10 years old), often through learning Portuguese at school.