1. William has already tidied up his room.
2. Caroline missed the schoolbus yesterday.
3. I've just finished my homework.
4. I cannot go out tonight. My grandparents have come to see us.
5. In 2004, the Olympic Summer Games took place in Athens.
6. Mary won the lottery last year.
7. We've already prepared dinner.
8. James found your ring in the garden yesterday.
9. He's just come home.
10. They bought their car two years ago.
11. I haven't seen anyone yet.
12. Phil didn't go to the cinema last night.
13. Have you read the book yet?
14. How many letters have they written so far?
15. When did he tell you that?