What dialect does the Dai language used by the Dai people in Gengma area of Lincang belong to? Tatay dialect in Thai, North Sub-dialect. Dehong Dai language is the language used by Dai people in Dehong Prefecture, Yunnan Province. It belongs to the northern sub-dialect of Thai with the Dai languages of Baoshan, lincang, Pu 'er, Kachin and Assam in Myanmar.