1) What is he checking now?
2) Why was he checking everything yesterday at 3 o'clock?
3) Who checks everything?
4) He didn't check everything yesterday.
5) Who will check everything tomorrow?
6) He will be checking everything at this time tomorrow.
7) Why are they so cruel?
8) Where they cruel?
9) Who will be cruel with animals, when it finds out that animals have the human mind?