UNESCO defines four levels of language endangerment between "safe" (not endangered) and "extinct":[1] According to Bangladesh Bureau of Statistics data from 2011, the country has 27 "small anthropological groups" consisting of 17,84,000 people in total.

Only 4 of the target languages have their own scripts — Chakma, Marma, Mru, and Meithei.

[4] It is used in the Sylhet tea garden area by Telugu, Santhali, Nepali and Rai communities as a lingua franca.

[3] The Hill Tracts, a forested upland area in southeastern Bangladesh, is home to more than a dozen indigenous peoples.

In north-eastern Bangladesh, Hari, Banai, Dalui, and Rajbongshi indigenous communities have started to use Bengali leaving their native languages due to the lack of social and economical recognition.