№1.
1. Are not.
2. Doesn't.
3. Do not.
4. Did not.
5. Didn't.
№2.
1. How old is he?
2. I like to sing.
3. When did you help your mum?
4. Did you wear funny costumes?
5. We invited many friends.
№3.
1. Bought.
2. Did not make.
3. Decorated.
4. Did you invite friends?