Answer:
1. Has John ever won a prize at a race?
2. I fell asleep yesterday when I was watching TV.
3. George has never been to Canada.
4. Tom is not back to England. He has been to Italy for three weeks.
5. We did a lot last Sunday.
6. I sometimes go to the cinema.
7. Nick worked hard yesterday.
8. I haven't found my ring yet which I lost at the party yesterday.
9. They built this castle in 1762.
10. Do you like to have something to eat? No, thank you. I just had dinner.
11. While Tom plays tennis, Ann takes a shower.
12. I don't see.
Explanation:
1. The question is in the Present Perfect Tense.
2. The first verb is in the Simple Past Tense, while the second is in the Past Continuous Tense.
3. The sentence is in the Present Perfect Tense.
4. The sentence is in the Present Perfect Tense.
5. The sentence is in the Simple Past Tense.
6. The sentence is in the Simple Present Tense.
7. The sentence is in the Simple Past Tense.
8. The first verb is in the Present Perfect Tense, while the second is in the Simple Past Tense.
9. The sentence is in the Simple Past Tense.
10. The sentence is in the Simple Past Tense.
11. Both verbs are in the Simple Present Tense.
12. The phrase is in the Simple Present Tense.