1. play -> playing
2. study -> studying
3. do -> doing
4. went -> go
5. sleep  -> sleeping
6. have -> had
7. broke -> break
8. go -> went
 

1. I was playing football when she called me.
2. Were you studying Math at 5 p.m. yesterday?
3. What was she doing while her mother was making lunch?
4. Where did you go last Sunday?
5. They weren't sleeping during the meeting last Monday.
6. He got up early and had breakfast with his family yesterday morning.
7. She didn't break the flower vase. Tom did.
8. Last week, my friend and I went to the beach on the bus.
9. While I was listening to music, I heard the doorbell.
10. Peter turned on the TV, but nothing happened.