Answer:
1. You were watching the football match when I saw you.
You were not watching the football match when I saw you.
Were you watching the football match when I saw you?
2. I was cycling when I met him.
I was not cycling when I met him.
Was I cycling when I met him?
3. They were eating when the lights went out.
They were not eating when the lights went out.
Were they eating when the lights went out?
4. We were swimming when he left the place.
We were not swimming when he left the place.
Were we swimming when he left the place?
5. She was running away when the teacher saw her.
She was not running away when the teacher saw her.
Was she running away when the teacher saw her?
6. While they were driving, it started raining.
It did not start raining while they were driving.
OR: While they were driving, it did not start raining.
(or possibly.... While they were not driving, it started raining)
Did it start raining while they were driving?
OR
While they were driving, did it start raining?
7. When you were sleeping, they took your photograph.
They did not take your photograph when you were sleeping.
OR: When you were sleeping, they did not take your photograph.
Did they take your photograph when you were sleeping?
OR: When you were sleeping, did they take your photograph?
8. I was singing as they passed by.
I was not singing as they passed by.
Was I singing as they passed by?
9. The man was laughing when the thief ran away.
The man was not laughing when the thief ran away.
Was the man laughing when the thief ran away?
10. John was walking when they took him away.
John was not walking when they took him away.
Was John walking when they took him away.?
Explanation:
For 6 and 7, answers can vary severely. Since I do not know which "underlined words" not to change, I had to guess.
Hope this helps somewhat anyway :)