Expressing Ability in the Past and in the Future: Could/Be able to

Let's get back to work. We've already seen the verb CAN in the present; now let's have a look at how we can express abilities in the past and in the future.

Past: Could... Was/Were able to
We use COULD to talk about general abilities in the past:

• "He could run a marathon when he was young." 

• "I could swim when I was five." 

• "I couldn't get around the city until I was 12." 

• "Could you read when you were 3?" 

We use WAS/WERE ABLE TO to express an ability on one particular occasion:

• "She was able to do the exam in 20 minutes." 

• "They were able to win the game." 

• "He wasn't able to stand on his feet." 

• "Weren't you able to drive back home?" 

*In questions the pronoun goes between "was/were" and "able to."

Future: Will/Won't be able to
The future form of the verb CAN is WILL BE ABLE TO:

• "When you get a job you will be able to afford the trip." 

• "I won't be able to pay them on time." 

• "She will not be able to carry out the project." 

• "Won't you be able to work for us?" 

*"Won't be able to" is the contraction for "Will not be able to." *We can express an idea in the future with CAN in for example "I can meet you tomorrow", but the future is in this case set by the adverb and not the verb.