Where does “thì phải” come from?

thì phải (Vietnamese) comes from Vietnamese phải, from Chinese 派, from English Pi, from Ancient Greek πῖ, from Ancient Greek πεῖ, from Proto-Semitic pay- — the mouth.

thì phải (Vietnamese): Used to indicate one's decent affirmation, yet with a need to confirm further from their speaking partner: possibly

Definitions

  1. Used to indicate one's decent affirmation, yet with a need to confirm further from their speaking partner: possibly

Ancestry of “thì phải”, step by step

thì phải traces back through two separate lines of ancestry.

via Vietnamese phải

StepLanguageWordMeaning
1Vietnamesephảiright; correct; obverse
2Chinese
3EnglishPiThe sixteenth letter of the Classical and Modern Greek alphabets and the seventeenth in Old Greek
4Ancient GreekπῖAlternative form of πεῖ
5Ancient Greekπεῖpi, the name for the sixteenth letter Π, π of the...
6Proto-Semiticpay-the mouth

via Vietnamese thì

StepLanguageWordMeaning
1VietnamesethìDated form of thời; the prime time in terms of...
2Chinese
3Old Chinese
Every word from Proto-Semitic pay-