III/
1. I remembered saying 'Happy Birthday' to Sarah.Did you?
2.She stopped drinking coffee so she would sleep better.
3.I forgot writing that letter.Sorry!
4. The TV doesn't work, but he's going to try to fix it.
5.I stopped buying petrol on my way to London yesterday.
6. Do you remember visiting your grandparents when you were little?
7.My sister tried cycling to work, but she didn't enjoy it so now she gets the bus.
IV/
1.Can you imagine not having a fridge?
2.They agreed not to say out late.
3.I feel like seeing a film tonight.
4.Did you mange to do the shopping?
5.My parents refuse to buy me a laptop
6.Harry can't do the face washing today.
7.He suggested to eat at a new restaurant.
8.She pretended not to see him.
9.We avoid driving to London in the rush hour.