phrase/puʁ kwa fɛʁ/
why? what for? to what end?
“– Venez vite parler au roi. – Et pour quoi faire ? répond le vilain. – À cause de votre grande science.” — – Come quickly to speak to the king. – And why? responded the peasant. – Because of your great knowledge.
Related: quoi faire
Literally, “to do what?”. Compare pourquoi.