1. I have been waiting here for 2 hours (positive)
I haven't been waiting here for 2 hours (negative)
Have I been waiting here for 2 hours? (question)
2. Mary has been cooking tasty dishes for 2 hours (positive)
Mary has not been cooking tasty dishes for 2 hours (negative)
Has Mary been cooking tasty dishes for 2 hours? (question)
3. Has Sam been shopping for 3 hours? (question)
Sam has been shopping for 3 hours (positive)
Sam has not been shopping for 3 hours (negative)
1. I have been waiting here for 2 hours (positive)
I haven't been waiting here for 2 hours (negative)
Have I been waiting here for 2 hours? (question)
2. Mary has been cooking tasty dishes for 2 hours (positive)
Mary has not been cooking tasty dishes for 2 hours (negative)
Has Mary been cooking tasty dishes for 2 hours? (question)
3. Has Sam been shopping for 3 hours? (question)
Sam has been shopping for 3 hours (positive)
Sam has not been shopping for 3 hours (negative)