| COULD |
could = past ability I knew how to do it in the past. I was able to do it in the past. |
(+) I could ride a bicycle when I was five years old. (-) I couldn't drive a car at age 10. (?) Could you skate when you were young? |
could = present & past possibility / opportunity It is/was possible. There is/was an opportunity for it.
| (+) You could ask your teacher for grammar help. (-) I couldn't go to the movies because I was busy. (?) Could you play football at your school? |
could = permission You have/had permission to do it. Is it OK if I do it? |
(+) I could walk to school alone when I was 7 years old. (-) I couldn't stay up late when I was young. (?) Could I have a cookie, please? |