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

10. My brother **is writing** a long novel at present.
11. We **are learning** English now.
12. He **is writing** to you?
13. Why didn't you listen while I **was speaking**?
14. Where are you? - I'm upstairs. I **am having** a bath.
15. You **haven't had** breakfast yet?
16. My little sister **drinks** milk every day.
17. The doctor sometimes **returns** home late.
18. They **are having** lunch in the cafeteria now.
19. They often **thank** me for what I do for them.
20. His uncle **taught** English in our school five years ago.
21. They **did not go** to the movies last Sunday.
22. You **found** my pen yesterday?
23. The light **went** out when we **were studying** our lesson.
24. There **will be** an English class in this room tomorrow evening.
25. They **painted** the school gate when we came.

Feel free to ask if you need further assistance!