Нужна ! надо поставить во времена: present future, past, past perfect. 1) if i (to come) home earlier, i (to prepare) dinner.2) if we (to live) in rome, francesco (to visit) us.3) if tim and tom (to be) older, they (to play) in our hockey team.4) if he (to be) my friend, i (to invite) him to my birthday party.5) if susan (to study) harder, she (to be) better at school.

1) If I had come home earlier, I  would have prepared dinner.
2) If we were in Rome, Francesco would visit us.
3) If Tim and Tom were older, they would play in our hockey team.
4) If he was my friend, I would invite him to my birthday party.
5) If Susan studies harder, she will be better at school.