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.