Reconstruction:Proto-Sino-Tibetan/rV-jak

• Proto-Sino-Tibetan: *riak/rjiak (Coblin, 1986); *(r-)jak (Jacques, 2017)
  • Proto-Tibeto-Burman: *s-r(y)ak (Matisoff, STEDT); *ryak (Benedict, 1972)

Schuessler (2007) assigned Chinese 夜 (yè) to → *ja (“night”) instead. Benedict (1972) listed Chinese 宿 as a reflex of this root, but the initials and vowels are difficult to reconcile.

Jacques (2017) derives Jingpho ya (“24-hour day”) from an unprefixed *jak, and the r-initial forms would be due to a denominal prefix (surviving in Japhug rɤ-).

*rV-jak

1. night
2. day (24 hours)

*rV-jak

1. to spend the night, overnight

• Old Chinese: 夜 (*ɴ.rak-s (B-S), *laːgs (ZS), “night”)
  • Middle Chinese: 夜 (jiaH)

    → Japanese: 夜 (や, ​ya)
    Korean: 야 (夜, ya)
    Vietnamese: dạ (夜)

    • Modern Mandarin
      • Beijing: 夜 (yè), /i̯ɛ⁵¹/
• Kamarupan
  • Kuki-Chin

    *riak-I, riaʔ-II (“to spend the night; overnight”) (VanBik, 2009)

    • Central Chin
      • Mizo: riak, riah (“to spend the night, to lodge for the night”)
• Himalayish
  • Tibeto-Kanauri
    • Bodic
      • Tibetan
        • Tibetan: ཞག (zhag, “day (24 hours)”) (> ཞག་པོ (zhag po, “day (24 hours); night”), ཞག་མལ (zhag mal, “night's lodging”))
• Naic
  • Proto-Naish: *Snak
    • Naxi: hal (classifier for nights), huq (“night”) (via lenited allomorph *Snaɣ)
    • Narua: hanq (“to spend the night”), han (classifier for nights)
• Lolo-Burmese: /*ʔrak/ ("night, spend the night") (Matisoff, 1972)
  • Burmish
    • Burmese: ရက် (rak, “day (24 hours)”)
    • Proto-Loloish: *ʔ-rakᴸ (“night”), *C-yakᴸ (“spend the night”) (Bradley, 1979)
  • Loloish
    • Northern Loloish
      • Yi (Liangshan): ꉖ (hxot, “(classifier) night”)
    • Central Loloish
      • Lisu (Southern): ꓦꓬꓼ (h̃jɑ̱̀, “(classifier) night”)
• Jingpho-Asakian
  • Jingpho: ya (“day, 24 hours”)

• *s-rjak (“oil, fat, grease”)