Раскройте скобки, выбирая требующееся время глагола:
1) My friend asked me who said (is playing, was playing) the piano in the sitting room.
2) He said he (will come, would come) to the station on see me off.
3) I was sure he (posted, had posted) the letter.
4) I think the weather (will be, would be) fine next week.