These people are sub-groups of Mongoloid Tai racial stock of Southeast Asia who came to the state and settled in the Brahmaputra valley during the ancient and medieval period.
While there were six branches of the greater Tai language in Assam, two languages- Tai-Ahom and Tai-Turung are already extinct while Tai Phake and Tai-Khamyang are critically endangered.
In 2006, Nath worked with an international team of researchers on a research project with the Singpho, Tangsa and Turung and Tai Phake communities to document their languages. In 2014, he took up the work of documenting the Tai Khamyang language.
“If a language is not transmitted from older to younger generation, its death is imminent. In the case of the Tai-Khumyang community, the language is spoken by a few people between the age of 70-80. That means the language will take only 20-25 years to become extinct if it doesn’t get passed on to the next generation. So there was an urgency to revive the language because along with its death, the traditional knowledge and ecological knowledge of the community will be lost forever.”
Organising week-long workshops, Nath started working closely with the community members and started documenting the oral and written materials related to their history, tradition, folk stories, songs, manuscripts, rituals etc. With the help of the community members, he produced storybooks for children in the Singpho and the Tai-Khamyang language to help them learn the language.
In 2009, using the materials collected from the community, Nath and his team of community members started Singpho Mother Tongue School in Ketetong village of Tinsukia district.