1 had known
2 would have recycled
3 had not polluted
4 would have grown
5 would not have become
May I visit my friend, please? May I eat chocolate, please? May I go for a walk, please? May I watch a DVD/TV, please? May I buy ice cream/chips, please?
1. Past simple
2. Present simple
3 present simple
4 past simple
5 future simple