1. This exercise isn't very difficult. not no nothing
2. It's easy. it its is
3. It won't take much time. not will not was
4. I think I'll be finished in five minutes. I will It will shall
5. I've answered four questions already. is am have
6. John's already done all of them. have is has
7. He's going home now. have is has
8. He's got a new car. have is has
Unit 6