Where does “mất công” come from?

mất công (Vietnamese) comes from Vietnamese Công, from Proto-Mon-Khmer koŋ, from Proto-Athabaskan *qʊ̓nʼ — fire.

mất công (Vietnamese): to put one's effort (into something that turns out to useless or not needed)

Definitions

  1. to put one's effort (into something that turns out to useless or not needed)

Ancestry of “mất công”, step by step

mất công traces back through two separate lines of ancestry.

via Vietnamese Công

StepLanguageWordMeaning
1VietnameseCông—
2Proto-Mon-Khmerkoŋto bend; to be bent; be bent
3Proto-Athabaskan*qʊ̓nʼfire

via Vietnamese mất

StepLanguageWordMeaning
1Vietnamesemấtto lose something; to die; to take
2Proto-Vieticɓǝt—
Every word from Proto-Athabaskan *qʊ̓nʼ →Every word from Proto-Mon-Khmer koŋ →Every word from Vietnamese Công →