Where does “-koːlʔ” come from?

-koːlʔ (Proto-Vietic) comes from Proto-Mon-Khmer kulʔ, from Proto-Mon-Khmer kəəlʔ — to support; to help.

Ancestry of “-koːlʔ”, step by step

StepLanguageWordMeaning
1Proto-Mon-Khmerkulʔ—
2Proto-Mon-Khmerkəəlʔto support; to help
Every word from Proto-Mon-Khmer kəəlʔ →Every word from Proto-Mon-Khmer kulʔ →