Modals of Ability
Modals of ability talk about….ability. That seems pretty obvious I think. We use modals (and phrasal modals) of ability to talk about present ability or past ability.
We use the modal can and the phrasal modal be able to (using the present of “be”) to talk about present ability. The phrasal modal really gives us a good understanding of what ability means. It means to be able to do something, and since we’re talking about present ability, it’s something that we’re able to do right now:
I am able to write in English.
She is able to speak Chinese.
They are able to make friends easily.
These all show current ability, things people have the ability to do right now, and we are able to use can to show the exact same ideas:
I can write in English.
She can speak Chinese.
They can make friends easily.
The only difference between the sentences with be able to and the sentences with can are that be able to is a little more formal than can.
To talk about an ability we had in the past but that we do not have now, we have to use past modals of ability: could and be able to (past of “be”):
I was able to play volleyball well in high school.
I could play volleyball well in high school.
They were able to pass the class last term because they studied.
They could pass the class last term because they studied.
With could, it’s important to make the past time clear in the sentence. If you don’t, it may sound like one of the other meanings of modals: probability/certainty. It will sound like it’s a possible choice or that you think it could happen in the future, not like it was a past ability.
Photo by Abby Gillardi on Flickr