Say what John was (was not) able to do when he was a little child.
John was four:
- roller-skate
- ride a tricycle
- fish
- read picture books
- play with his toys
- play basketball

When John was four he wasn't able to roller-skate.
When he was four he was able to ride a tricycle.
When John was four he wasn't able to fish.
When John was four he was able to read picture books.
When John was four he was able to play with his toys.
When John was four he wasn't able to play basketball.