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 am 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 am not cleaning the blackboard. Am I cleaning the blackboard?
8. My sister Chris and David aren`t getting married today. Are my sister Chris and David getting married today?
9. I'm not always thinking about her three days. Am I always thinking about her three days?
10. Ingrid and Dorothy aren`t giggling and whispering together. Are Ingrid and Dorothy giggling and whispering together?
Present Perfect Continuous - We have been cleaning the flat since the morning.
Past Perfect Continuous - I had been watching TV for two hours when my parents came home yesterday.
Future Continuous - My sister will be helping our mum at this time tomorrow.
Future Perfect - Ann will have done shopping by the noon tomorrow.
Future Perfect Continuous - I will have been watching TV for two hours when my parents come home tomorrow.