pridemandi

This one comes apart cleanly, and the seam is a real and productive pattern. Demandi is to ask. Put the preposition pri on the front and the thing the asking is about becomes the direct object: you demandas al iu pri io, but you pridemandas iun. The person gets the accusative. That is what the pri- prefix does in general - it drags the prepositional complement into the object slot.

The same trick built prilabori (to work over, to process) out of labori, and it also gives priparoli (to discuss), pripensi (to think over), priskribi (to describe), prizorgi (to look after). Learn the mechanism once and six words arrive free. That is the Esperanto bargain in miniature.

Register: pridemandi is heavier than demandi. It is what the police do, what a court does, what a suspicious parent does. If you just want to ask your friend something, demandi is the word; pridemandi implies a session and probably an unwilling answerer. The noun is pridemando, an interrogation.