Where does “สอบตก” come from?

สอบตก (Thai) comes from Thai ตก, from Proto-Tai tokᴰ — to drop.

สอบตก (Thai): to fail an exams

Definitions

  1. to fail an exams

Ancestry of “สอบตก”, step by step

สอบตก traces back through two separate lines of ancestry.

via Thai ตก

StepLanguageWordMeaning
1Thaiตกto fall; to drop
2Proto-Taitokᴰto drop

via Thai สอบ

StepLanguageWordMeaning
1Thaiสอบto examine; to subject to an examination or test;...
Every word from Proto-Tai tokᴰ →Every word from Thai ตก →