The Kam or Gam language (lix Gaeml), also known as Dong (Chinese: 侗语; pinyin: Dòngyǔ), is a Kam–Sui language spoken by the Dong people. Ethnologue distinguishes three Kam varieties as separate but closely related languages.^[1]

Almost 1.5 million speakers of Southern Dong were counted in the 1990 language census, from a total of 2.5 million people in the Dong ethnic group. The Southern Dong live primarily in Rongjiang, Jinping, Liping, Zhenyuan, and Congjiang counties in Guizhou Province; Longsheng, Sanjiang, and Rongshui counties in northeastern Guangxi; and Tongdao County in Hunan Province. Two Dong villages are also located in northern Vietnam, although only one individual in Vietnam is still able to speak Dong.^[2]

The Kam language can be divided into two major subdivisions: Southern Kam and Northern Kam.^[3] Northern Kam displays more Chinese influence and lacks vowel length contrast, while Southern Kam is more conservative. Language varieties closely related to or part of Kam include Cao Miao and Naxi Yao. A northern Pinghua variety called Tongdao Pinghua, spoken in Tongdao County, Hunan, has also been significantly influenced by Kam.

Southern Kam

• First lectal area: Róngjiāng Zhānglǔ (榕江县章鲁村), Lípíng Hóngzhōu (黎平县洪州镇), Jǐnpíng Qǐméng (锦屏县启蒙镇) in Guizhou; Tōngdào (通道县) in Hunan; Longsheng (龙胜县) and Sanjiang Dudong (三江侗族自治县独峒乡) in Guangxi
• Second lectal area: Lípíng Shuǐkǒu (黎平县水口镇), Cóngjiāng Guàndòng (从江县贯洞镇), Róngjiāng Píngjiāng (榕江县平江乡) in Guizhou; Sānjiāng Hélǐ (三江侗族自治县和里村) in Guangxi
• Third lectal area: Zhènyuǎn Bàojīng (镇远县报京乡) in Guizhou
• Fourth lectal area: Róngshuǐ (融水苗族自治县) in Guangxi

Northern Kam

• First lectal area: Tiānzhù Shídòng (天柱县石洞镇), Sānsuì Kuǎnchǎng (三穗县款场), Jiànhé Xiǎoguǎng (剑河县小广侗寨) in Guizhou; also Jǐnpíng Jiǔzhài (锦屏县九寨) in Guizhou^[4]
• Second lectal area: Tiānzhù Zhǔxī (天柱县注溪乡) in Guizhou
• Third lectal area: Jǐnpíng Dàtóng (锦屏县大同乡) in Guizhou

Long (2012:19-20)^[5] classifies the Kam lectal areas (dialects) as follows.

Southern Kam

• Lectal area 1
  • Chejiang, Rongjiang County 榕江县车江
  • Longcheng, Tongdao County 通道县陇城
  • Pingdeng, Longsheng County 龙胜县平等
  • Chengyang, Sanjiang County 三江县程阳
  • Hongzhou, Liping County 黎平县洪州
• Lectal area 2
  • Zhaihao, Rongjiang County 榕江县寨蒿
  • Shuikou, Liping County 黎平县水口
  • Guidong, Congjiang County 从江县贵洞
  • Heli, Sanjiang County 三江县和里
• Lectal area 3
  • Zhaihuai, Rongshui County 融水县寨怀
• Lectal area 4
  • Pindong, Rongshui County 融水县聘洞

Northern Kam

• Lectal area 1 (Highland Dong 高坡侗)
  • Shidong, Tianzhu County 天柱县石洞
  • Kuanchang, Sansui County 三穗县款场
  • Jiuzhai, Jinping County 锦屏县九寨
  • Xiaoguang, Jianhe County 剑河县小广
• Lectal area 2 (River Dong 河边侗)
  • Datong, Jinping County 锦屏县大同
  • Sanmentang, Tianzhu County 天柱县三门塘
  • Lannichong, Jingzhou County 靖州县烂泥冲
• Lectal area 3
  • Zhuxi, Tianzhu County 天柱县注溪
  • Zhongzhai, Xinhuang County 新晃县中寨
• Lectal area 4
  • Qimeng, Jinping County 锦屏县启蒙
• Lectal area 5
  • Baojing, Zhenyuan County 镇远县抱京

In Congjiang County, Dong consists of three dialects: Jiudong 九洞 (similar to Chejiang 车江 Dong), Liudong 六洞 (similar to Liping 黎平 Dong), and another dialect spoken in Xishan 西山, Bingmei 丙梅, and Guandong 贯洞 (similar to Sanjiang 三江 Dong) (Congjiang County Gazetteer 1999:109).

In Suining County, Hunan, Dong is spoken in Lianfeng 联丰 (including Duolong 多龙村), Huangsangping 黄桑坪, Le'anpu 乐安铺, and other nearby locations.^[6] In Chengbu County, Hunan, Dong is spoken in Yanzhai 岩寨, Chang'anying 长安营, and Jiangtousi 江头司.^[7]

Kam is also spoken in the single village of Đồng Mộc, Trung Sơn Commune, Yên Sơn District, Tuyên Quang Province, northern Vietnam,^[8] where there are about 35 Kam people (Edmondson & Gregerson 2001).^[9] The Kam of Đồng Mộc had migrated to Vietnam from China about 150 years ago. The Kam variety spoken in Đồng Mộc is most similar to that of Lípíng Shuǐkǒu (黎平县水口镇) in southeastern Guizhou.

In China, a total of seven counties designated as Dong Autonomous Counties (侗族自治县).

• Yuping Dong Autonomous County, Guizhou
• Sanjiang Dong Autonomous County, Guangxi
• Longsheng Various Nationalities Autonomous County, Guangxi
• Xinhuang Dong Autonomous County, Hunan
• Zhijiang Dong Autonomous County, Hunan
• Jingzhou Miao and Dong Autonomous County, Hunan
• Tongdao Dong Autonomous County, Hunan

According to the Shaoyang Prefecture Gazetteer (1997), language varieties closely related to Southern Kam are spoken in Naxi 那溪, Dongkou County (which had 4,280 ethnic Yao in 1982 (Chen 2013:39)) and Lianmin 联民, Suining County. However, they are officially classified by the Chinese government as ethnic Yao, not Dong. Chen Qiguang (2013:39)^[10] reports that the ancestors of Naxihua 那溪话 speakers had migrated to their current location from Tianzhu, Liping, and Yuping counties of southeastern Guizhou during the early 15th century.

Kam has two main orthographies: the Chinese academic developed system and the independently developed system by Ngo Van Lyong for Southern Kam as spoken in Rongjiang.^[11] The Chinese system is most commonly used by linguists and has similarities to other Chinese Kra–Dai language orthographies (such as Zhuang). The Ngo Van Lyong system was inspired by the Vietnamese alphabet and is made for speakers and learners.

While the Chinese system is the most well known, most Kam speakers are not literate.^{[citation needed]}

The Chinese orthography for Kam orthography has 32 syllable-initial consonants; seven of them (tʃ-, tʃʰ-, ʃ-, ɻ-, f-, ts- and tsʰ-) only occur in recent loanwords from Chinese.

The Ngo Van Lyong orthography for Southern Kam has 28 syllable-initial consonants.

The Chinese orthography for Kam has 64 syllable finals; 14 of them occur only in Chinese loans and are not listed in the table below.

The phonetic value of the vowel in the finals spelled -ab, -ad and -ag, is [ɐ] in syllables that have the tones -l, -p and -c (see table below); in syllables with tones -s, -t and -x, it is [a]. The phonetic value of the vowel in the finals spelled -eb, -ed and -eg, is [ə] in syllables that have the tones -l, -p and -c; in syllables with tones -s, -t and -x, it is [e].

The Ngo Van Lyong orthography for Southern Kam has 116 syllable finals.

Kam is a tonal language. Open syllables can occur in one of nine different tones, checked syllables in six tones (so-called entering tones), so that the traditional approach counts fifteen tones. As with the Hmong alphabet, the Chinese orthography marks tones with a consonant at the end of each syllable.

The Ngô Văn Lương orthography marks tones via diacritics written above or below the vowel as with the Vietnamese alphabet and only features 6 tones.^{[citation needed]}

• Ōu Hēngyuán 欧亨元: Cic deenx Gaeml Gax / Dòng-Hàn cídiǎn 侗汉词典 (Kam–Chinese dictionary; Běijīng 北京, Mínzú chūbǎnshè 民族出版社 2004), ISBN 7-105-06287-8.

• Long, Y., Zheng, G., & Geary, D. N. (1998). The Dong language in Guizhou Province, China. Summer Institute of Linguistics and the University of Texas at Arlington publications in linguistics, publication 126. Dallas, TX: Summer Institute of Linguistics. ISBN 1-55671-051-8
• Yang, Tongyin & Edmondson, Jerold A. (2008). Kam. In Anthony V. N. Diller and Jerold A. Edmondson and Yongxian Luo (eds.), The Tai-Kadai Languages, 509-584. London & New York: Routledge.

• Southern Dong word list from the Austronesian Basic Vocabulary Database
• Dong-language Swadesh vocabulary list of basic words (from Wiktionary's Swadesh-list appendix)