CAN (PAST AND FUTURE)
THE SIMPLE PAST TENSE
In the past tense "can" becomes "could" or "was able to".
"Can" becomes "was able to" when the action is a particular achievement in the past.
When we were young, I was able to beat you at tennis only once.
"Can" becomes "could" when the action is a general ability that the person had.
When we were young, I could always beat you at tennis.
"Can" also becomes "could" with certain 'verbs of perception': see, hear, taste, feel, remember, understand and guess. In other words, verbs which describe information taken in through the senses, or actions performed by the brain.
I could hear her scream.
She could remember a little Spanish from her schooldays.
Now read these sentences and change them into the past tense, using "could", or "was able to". Type the whole sentence in the empty text box, making any other changes which are necessary. Then click the answer box.
THE FUTURE TENSE
In the future tense "can" becomes "will be able to", although "can" is used to when you are deciding now about something which will happen in the future.
1.When I have a car, I will be able to drive to school.
2.When I have more money, I will be able to pay you.
3.I can come on holiday with you in July.
4.I can be at your house by 8.30.
In Examples 3 and 4 a definite decision about the future is expressed.
Now read these sentences. Type the sentence again in the text box, but put it in the future tense. Use the correct future form of "can" together with the verb in brackets. Then click the answer box to see if you have used the right auxiliary correctly.