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Language Lineage

Tai

The branch of Thai, Lao, Shan and Zhuang. Proto-Tai had three tones plus 'dead' checked syllables, and every tone later split in two according to the old initial consonant.

c. 1st millennium BCE – presentFrom Guangxi and Guizhou southwest to Laos, Thailand, Myanmar and Assam
On this page
  1. Three Groups
  2. The Great Tone Split
  3. Where its languages are spoken
  4. Turning points

01

Three Groups

Li Fang-Kuei, whose Handbook of Comparative Tai (1977) founded modern Tai reconstruction, divided the Tai languages into Northern, Central and Southwestern groups. Northern Tai (Zhuang, Bouyei) stayed in southern China, and Southwestern Tai (Thai, Lao, Shan) spread across mainland Southeast Asia. Recent work by Pittayawat Pittayaporn treats the tree as a series of splits in southern China, with Southwestern Tai as a late branch.

02

The Great Tone Split

Proto-Tai had three tones on 'live' syllables, conventionally A, B and C, plus 'dead' syllables ending in a stop (D). Later, each tone split according to the kind of consonant a syllable began with, voiced or voiceless, aspirated or glottalised, so that the modern languages have five, six or more tones in patterns that correspond regularly across the branch. The Thai script still marks the old consonant classes, and readers use them to work out the tone.

On the map

Where its languages are spoken

Spoken todayShading marks whole countries, not the regions within them.
  1. ThailandSouthwestern Tai c. 50 million
  2. ChinaNorthern Tai c. 12 million · Central Tai c. 4 million · Southwestern Tai c. 1 million
  3. VietnamCentral Tai c. 3 million · Southwestern Tai c. 1.5 million
  4. LaosSouthwestern Tai c. 4 million
  5. MyanmarSouthwestern Tai c. 3 million

Figures are rough first-language estimates, rounded, from censuses and Ethnologue. Counts for small or scattered communities are especially uncertain.

Rings along the limb

Turning points

Oldest first.

  1. Sound lawc. 1000 – 1500 CEContested

    The Great Tone Split

    tones A B C (+ D) split by initial voicing → 5–9 tones; voiced initials devoice

    Each of the Proto-Tai tones splits in two, or more, according to whether the syllable began with a voiced or a voiceless consonant, and the old voiced consonants then lose their voicing. The Thai script's 'high', 'mid' and 'low' consonant classes still encode the difference. The dating is debated.

    Figures · Li Fang-Kuei (1902–1987)

    Compare with other stress and prosody across families →

    Sources (2)
    • Li, Fang-Kuei. 1977. A Handbook of Comparative Tai. Honolulu: University of Hawaii Press.
    • Haudricourt, André-Georges. 1961. Bipartition et tripartition des systèmes de tons dans quelques langues d'Extrême-Orient. Bulletin de la Société de Linguistique de Paris 56.
  2. Splitc. 1st millennium CEContested

    Northern and Southwestern Tai part

    The Tai dialects of Guangxi and Guizhou diverge, and the ancestors of Southwestern Tai begin to move southwest. The internal structure of Tai is debated.

    Sources (1)
    • Pittayaporn, Pittayawat. 2009. The Phonology of Proto-Tai. PhD dissertation, Cornell University.