He keeps his pet at home1. Does he keep his pet at home?
2. Does he keep his pet or his sister's pet at home?
3. What does he keep at home?
4. He keeps his pet at home, doesn't he?
5. Who keeps his pet at home?
Animals were ill1. Were animals ill?
2. Were animals ill or healthy?
3. Who was ill?
4. Animals were ill, weren't they?
5. How did the animals feel?