1) Use the past perfect
1 jim wasnt at work when his boss arrived. He.....already....(go) home
2 we arrived at the cinema late. The film.... Already...(begin)
3 they werent eating when i entered the dining room. They .... Already...(finish )dinner
4 i invited Ann to the cinema but she refused. She....already...(arrange) to go to tge theatre with Sam.
5 i was pleased to see Nora again. I ....(not see) for 5 years
6 i wanted to go to the rock festival before car. I forgot that i .....(sell) it

2) use perfect or past simple
1 the house was quiet when i got home. Everybody...(go) to bed
2 i felt tired when i got home so i....(go) straight to bed
3 sorry im late . the car .....(break) down on my way here
4 i saw a car by the side of the road. It....(break) down