If this was the perfective form of mówić (which I don't know), would it mean, "What did you say." Because the act of saying was completed. I am still trying to wrap my head around perfective and imperfective.
So basically in the middle of a conversation when you gazed off day dreaming you say 'Przepraszam, co mówiłeś?', is that the situation? :D
Yes. Exactly that.
„Co powiedziałeś !?” or „Coś powiedział !?” is preferred when you are angry about what other person said.
I agree that "What were you saying?" is better, but I wrote "What were you talking about," and it was marked as incorrect. Is my version not possible?