12) If the weather (to be) fine, my family (to go) on a trip.
13) I (to give) a present if he (to invite) me to his birthday party.
14) Of course we (to help) you if we (not be) busy.
15) I ( to see) my mother before I (to fly) to London.
16) If my daughter (not to come) in time, I (to go) without her.
17) They (to wait) until we (to come).
18) we (not to send) you the money before we (to leave).
19) If Jane (to come) to see me, we (to listen) to the music.
20) When they (to talk) to her, they (to give) her your news.