Correct the sentences below (if necessary) using Past Simple and Past Progressive tenses.

Here are the corrected sentences with explanations: 1. Mary was painting her room when her father came home. *Explanation:* We use Past Progressive (`was painting`) because Mary was in the process of painting when her father arrived. Past Progressive describes an action in progress at a specific time in the past. 2. What were you doing at 7 o'clock in the evening? *Explanation:* The subject is "you", which is plural, so the verb "was" should be corrected to "were". 3. Jane bought a very nice dress yesterday. (Correct) 4. I was writing a letter all evening. *Explanation:* The original sentence suggests the action continued throughout the entire evening. We use Past Progressive (`was writing`) to indicate a continuous action in the past. 5. Did you know the answer? *Explanation:* The past form of 'know' is 'knew'. The correct structure for a question in the past simple is 'Did + subject + base form of verb?' 6. This time last year, we weren't studying French. (Correct) 7. Sally was doing her homework while I was listening to my favourite radio station. *Explanation:* Both actions were happening simultaneously, so we use Past Progressive (`was listening`). 8. Andrew wasn't eating pizza yesterday. (Correct) 9. I didn't talk to my sister last night. (Correct) 10. Were you playing football when your cat fell out of the window? *Explanation:* The sentence requires a continuous action in the past interrupted by another event. We use Past Progressive (`were playing`) for the continuous action and Past Simple (`fell`) for the interrupting event. 11. Last night Martin and Ann were studying from 2 to 6. *Explanation:* Since the subjects are Martin and Ann, we need a plural form of the verb 'to be' (were). Because of the time frame (from 2 to 6), we use Past Progressive (`were studying`) to show the duration of the action. 12. Did he come home late? *Explanation:* The original sentence is already correct in its meaning, but in english the auxiliary verb 'did' requires the base form of the verb 'to come'. 13. What were you doing last weekend? *Explanation:* The correct auxiliary verb to use with 'you' in the past tense is 'were'. 14. Tim didn't go to Italy last week. (Correct) 15. When he was breaking this vase yesterday, he was watching football. *Explanation:* Two actions were happening simultaneously in the past. Therefore we should use Past Progressive. When he `was breaking` the vase, he `was watching` football. 16. Three days ago, I spent a very interesting evening at my friend's house. *Explanation:* We need the past simple form of the verb 'spend', which is 'spent'. 17. Were you sleeping at midnight yesterday when I called you that time? *Explanation:* Since you were sleeping at midnight, we use past progressive (`were you sleeping`) and it was interrupted by the call. Therefore, the second action is in Past Simple, which is already used correctly. 18. Did you cook dinner when my sister called you? *Explanation:* Here, one action interrupts another, so we use Past Simple (`called`). 19. I was making this project for three days. *Explanation:* As the sentence specifies that the project was in process for a duration of time, we use Past Progressive (`was making`). 20. She was having a shower when her mobile rang. *Explanation:* The correct sentence is 'She was having a shower when her mobile rang'. We use Past Progressive (`was having`) for the continuous action that was interrupted by a sudden event.