Reconstruction:Proto-Sino-Tibetan/b-ka-(n/m/ŋ)

• Proto-Sino-Tibetan: *b-kɑ-n (Coblin, 1986)
  • Proto-Tibeto-Burman: *b-ka-(n/m/ŋ) (Matisoff, STEDT); *b-ka-n (Matisoff, 2003; Mortensen, 2012); *ka (Benedict, 1972; Weidert, 1987; LaPolla, 1987); *ka (*B) (Coblin, 1986); *kɑ (Chou, 1972)

Derivative: Proto-Sino-Tibetan *kak (“difficult, hard”).

Compare Proto-Tai *Ĉ.qɤmᴬ (“bitter”) (Thai ขม (kǒm), Lao ຂົມ (khom)); also compare: Thai ขื่น (kʉ̀ʉn), Lao ຂື່ນ (khư̄n, “bitter, astringent, ascerbic”).

*b-ka-(n/m/ŋ)

1. bitter
2. bile
3. liver

• Old Chinese: 苦 /*kʰˤaʔ/ (B-S), /*kʰaːʔ/ (ZS) ("bitter; a bitter plant"); /*kʰˤa-s/ (B-S, unlisted), /*kʰaːs/ (ZS) ("difficult, hardship"); 肝 /*s.kˤar/ (B-S); /*kaːn/ (ZS) ("liver")
  • Middle Chinese: 苦 (kʰuoX, kʰuoH/), 肝 (kɑn)

• • →   Japanese:  苦 (く, ​ku)
          Korean:  고 (苦, go)
          Vietnamese:  khổ (苦)

• • →   Vietnamese:  khó (“hard, difficult; delicate”)

• • →   Japanese:  肝 (かん, ​kan)
          Korean:  간 (肝, gan)
          Vietnamese:  can (肝)

• • →   Vietnamese:  gan (“liver”)

    • Modern Mandarin
      • Beijing: 苦 (kǔ, /kʰu²¹⁴/), 肝 (gān, /kan⁵⁵/)
• Himalayish
  • Tibeto-Kanauri
    • Bodic
      • Tibetan
        • Written Tibetan: ཁ་བ (kha ba, “bitter”), དཀ་བ (dka ba, “difficult”)
• Naic:
  • Naish:
    • Naxi: ka (“bitter”)
• Nungish:
  • Rawang: ka (“bitter”)
  • Trung/Drung/Dulong: ka (“bitter”)
• Lolo-Burmese
  • Burmish
    • Burmese: ခါး (hka:, “bitter”)
  • Loloish
    • Northern Loloish
      • Yi (Liangshan): ꈌ (ke, “bitter”)
    • Central Loloish
      • Lisu (Northern): ꓘꓪꓽ (kʰwà, “bitter, too salty”)
      • Lolopo: kar (“bitter”)
• Karen: *khaᴮ (Luangthongkum, 2013)
  • Sgaw: ခၣ် (khà, “bitter”)

• *m-sin (“liver, heart, bile, bitter”)
• *m-ka (“mouth, opening, door”)
• *ka (“word, speech, language”)
• *tsa (“salt”)