Where does “trời ạ” come from?

trời ạ (Vietnamese) comes from Vietnamese a, from French a, from French elle, from Old French ele, from Latin āla, from Latin axla, from Latin axis, from Proto-Italic aksis — to drive.

trời ạ (Vietnamese): for heaven's sake; for God's sake; for Christ's sake; for Pete's sake; for goodness' sake

Definitions

  1. for heaven's sake; for God's sake; for Christ's sake; for Pete's sake; for goodness' sake

Ancestry of “trời ạ”, step by step

trời ạ traces back through two separate lines of ancestry.

via Vietnamese a

StepLanguageWordMeaning
1VietnameseaThe name of the Latin-script letter A;...
2Frenchaa, The name of the Latin-script letter A;...
3Frenchelleshe; it; disjunctive form of elle; her; à elle =...
4Old Frencheleshe; wing
5Latinālaa wing appendage of an animal's body that enables it to fly
6Latinaxla
7LatinaxisAn axletree of wagon, car, chariot; The North...
8Proto-Italicaksis
9Proto-Indo-Europeanh₂eḱs-axis, axle
10Proto-Indo-Europeanh₂eǵ-to drive

via Vietnamese trời

StepLanguageWordMeaning
1Vietnamesetrờithe sky; weather; a generic deification of the...
2Proto-Vieticb-ləːjsky
3Proto-Mon-Khmerbriiʔsky; rain; forest
Every word from Proto-Indo-European h₂eǵ-