As noted by Li and Zhou (1999),[3] Gelao shares much vocabulary with the Hlai and Ong Be languages, suggesting contact with Pre-Hlai speakers before their migration to Hainan.
Zhang Jimin estimated a total of over 10,000 Gelao speakers in the early 1990s, while Li Jinfang places this number at 3,000 in 1999.
[5] This number is rapidly declining, as the Gelao are intermarrying with the neighboring Han, Bouyei, and Miao.
The Mulao number 28,000 people, and are distributed in Majiang, Kaili, Huangping, Duyun, Weng'an, Fuquan, and other counties of southeastern Guizhou.
[7] One dialect is represented by the datapoints of Bamaozhai 巴茅寨 and Madizhai 马碲寨 of Xuanwei District 宣威区, Majiang County (Luo 1997:105, 115), and the other by Bailazhai 白腊寨, Lushan Town 炉山镇, Kaili City (Luo 1997:189); the latter is also spoken in Dafengdong 大风洞, Pingliang 平良, and Chong'anjiang 重安江.
[8] The extinct Tuman language (土蛮语) of Sinan County, Guizhou was a variety of Gelao.
The Red Gelao people, who call themselves the va35 ntɯ31, send brides back and forth among the villages of Na Khê and Bạch Đích (or Bìch Đich) in Yên Minh District, Hà Giang Province, Vietnam and another village in Fanpo, Malipo County, Yunnan, China[14] (autonym: u33 wei55) in order to ensure the continual survival of their ethnic group.
Edmondson (1998) reports that there are also Red Gelao people in Cán Tí, Quản Bạ District and Túng Sán, Hoàng Su Phì District[15] who no longer speak any Gelao, and speak Hmong, Tay, or Vietnamese instead.
Gelao is not well documented, having only been studied by a few scholars such as Li Jinfang, Jerold A. Edmondson, Weera Ostapirat, and Zhang Jimin.
The Encyclopedia of the World's Endangered Languages (2007), based on information from He (1983), groups Gelao into five subdivisions.
[28] The most extensively studied varieties are the Wanzi and Zhenfeng dialects, while the most endangered one is Red Gelao.
The Gelao speakers of "Donie" do31 ȵe31 village, Aga Township 阿嘎乡, Shuicheng County 水城县 originally migrated from Houzitian several decades ago; there are only a few elderly rememberers of that variety left.
Zhang (1993:300) notes that the Moji (磨基) Longlin dialect of White Gelao makes especially extensive use of prefixing syllables before nouns, verbs, and adjectives.
In Guizhou, there are several manuscripts that have word lists of Gelao varieties written using Chinese characters.
In 2009, a book allegedly written in a native Gelao script was found in Guizhou, China,[35] but scholarship reveals it is certainly fake.