The expression “If I had known, (I would..)” in English can be expressed using the phrase “(ถ้า)รู้อย่างนี้ [tâa rúu yàang níi].” “ถ้า [tâa]” means “if” and can be omitted, “รู้ [rúu]” means “to know,” and “อย่างนี้ [yàang níi]” literally means “like this.”
Examples
(ถ้า)รู้อย่างนี้ ไม่มาแน่นอน
[(tâa) rúu yàang níi, mâi maa nâe nawn]
If I had known, I wouldn’t have come.…