1) He is able to go to University next year.
2) I was able to play football when I was fifteen.
3) You are not able to drive a car if you are six.
4) Paul wasn't able to write two years ago.
5) My mother is able to cook very well.
6) I am not able to know everything.
______________________________
can = to be able to
"To be" надо поменять на соответствующую форму глагола to be, которая подходит для местоимения.