1. We lost the ball while we were playing football.
2. When I saw your sister she was walking to school.
3. While Marek was doing his homework his dad came home.
4. They were running when I saw them.
5. I got home while you were cooking
6. She was dancing when she fell
7. He met a new friend while he was traveling
8. When I saw you, you was talking to Mr. Wood