Bonjour je ne comprend pas cette exo pouvez vous m'aider svp avec des explication si possible merci

I. Conjugue les verbes entre parenthèses au preterit en BE + V- ING:
1. The dog ………………………. (bark) when I went out last night.
2. While I …………………….. (sleep), John stole my pen.
3. When he arrived, we …………………………..(not/study) any longer.
4. Though it ……………………. (rain) we went to the cinema last night.
II. Conjugue les verbes entre parenthèses au PAST PERFECT:
1. When I went to the car park, I found that my car …………………….. ( disappear).
2. Peter ……………………....…... (live) in Paris for 4 years before he could speak French
fluently.
3. They were angry because they ……………….. (wait) for too long.
4. The locals were amazed because they ………… never…………….. ( see) a horse before