1. The teacher isn't explaining a grammar rule.
Is the teacher explaining a grammar rule?
2. The woman isn't playing with a child.
Is the woman playing with a child?
3. The boys aren't skating.
Are the boys skating?
4. I'm not waiting for them.
Am I waiting for them?
5. The children aren't having supper.
Are the children having supper?
6. It isn't raining.
Is it raining?
7. I'm not cleaning the blackboard.
Am I cleaning the blackboard?