1. My brother can watch TV from morning till evening.
Can my brother watch TV from morning till evening?
What can my brother watch from morning till evening?
2. My sister can speak English very well.
Can my sister speak English very well?
Who can speak English very well?
3. My brother could play the piano very well when he was a child.
Could my brother play the piano very well when he was a child?
Who could play the piano very well when he was a child?
4. Yesterday I could go to the theatre, but I was tired and went home.
Could I yesterday go to the theatre, but I was tired and went home?
When could I go to the theatre, but I was tired and went home?
5. My sister will be able to help you tomorrow.
Will my sister be able to help you tomorrow?
When will my sister be able to help you?
6. These students will be able to study German next year.
Will these students be able to study German next year?
Who will be able to study German next year?