Here are the correct forms of the verbs for each sentence:

1. We wish you **had arrived** yesterday. (arrive)
2. I wish I **hadn't lost** the answers. (not lose)
3. We wish you **had known** what to do last year. (know)
4. I wish that he **would visit** us next year. (visit)
5. She wishes that she **were** at home now. (be)
6. I wish I **had heard** the news. (hear)
7. You wish that he **had helped** you last week. (help)
8. I wish I **could find** the subject more interesting. (find)
9. He always wishes he **were** rich. (be)
10. The boy wishes that he **would win** the competition the next day. (win)
11. I wish you **had left** earlier yesterday. (leave)
12. We wish they **had come** with us last weekend. (come)
13. They wish he **had come** with them the next day. (come)
14. They wish we **hadn't given** them some food yesterday. (give)
15. I wish I **were** a doctor when I grow up. (be)
16. I wish I **would** see you tomorrow. (see)
17. They wish it **would not rain** tomorrow. (not rain)
18. I wish I **were** taller. (be)
19. I wish it **would be** fine on the party next week. (be)
20. I wish tomorrow **would be** a beautiful day. (be)
21. I wish I **knew** her address. (know)