Their language belongs to the Tibeto-Burman family, but it is suggested that their language is close to Tshangla (Sharpa) and Bumthangkha. It is also suggested that their dialect is considered a Monpa dialect, and it seems that they have been largely abosorbed into the Monpa people.
External Links
Tshangla language (http://www.kuenselonline.com/article.php?sid=3051&PHPSESSID=492b4f287f52d461af5742efac5dff62)