Ответ:
- He sold his house in the city and bought a new one by the sea. Buy has the irregular past form bought.
- We played video games and then we went to the party. The two completed actions are in the past simple.
- I felt very excited while we were listening to the concert. The past continuous describes the ongoing action.
- They were standing at the cooker while they were making dinner. Both actions were happening at the same time.
- It was raining when we went to the park. The past continuous describes the ongoing weather; the past simple describes the event.
- I went out just after you arrived. The actions happened successively, so the past simple is used.
