It's illegal to drive without wearing a seatbelt.
1 Is it illegal to drive without wearing a seatbelt?
2 What is illegal to do?
3 Is it legal or illegal to drive without wearing a seatbelt?
4 It's illegal to drive without wearing a seatbelt, isn't it?
We always eat eggs for breakfast.
1 Do we always eat eggs for breakfast?
2 What do we always eat for breakfast?
3 Do we always eat eggs or sandwiches for breakfast?
4 We always eat eggs for breakfast, don't we?