1. Bob can't answer difficult questions now, but when he is older he will be able to do it.
2. Bob can't fly a plane now, but when he is older he will be able to fly a plane.
3. Bob can't go to university now , but when he is older he will be able to go to university.
4. Bob can't work on the computer now, but when he is older he will be able to work on it.
5. Bob can't have a bank card now, but when he is older he will be able to have it.