[citation needed] Unlike most written Yi languages, Nasu uses the Pollard script.

According to the Guizhou Ethnic Gazetteer (2002),[2] Yi autonyms include Nasu 哪苏,[3] Tusu 兔苏,[4] Lagou 腊勾,[5] Guo 果,[6] and so forth.

[8] Chen, et al. (1985:108) recognizes 3 major varieties of Eastern Yi (i.e., Nasu) that are spoken in Yunnan and Guizhou provinces, namely Dianqian 滇黔 (Yunnan-Guizhou), Pan 盘县 (Pan County of Guizhou), and Diandongbei 滇东北 (Northeastern Yunnan).

Nasu proper used in Wuding, Luquan, and the suburbs of Kunming, and Wusa used in Guizhou and the bordering areas of Eastern Yunnan.

David Bradley (1997) distinguishes three main dialects of Nasu: Lama (2012) determined that Nasu (Western) is more closely related to Gepo than it is to the others: There is distinction between tight-throat vowels and lax-throat (plain) vowels.