Can vs could vs be able to
- Exercises with answers
- PDF worksheets
- Grammar rules with examples
English grammar books PDF
PDF book 1: English tenses exercises
PDF book 2: English grammar exercises
PDF book 3: English grammar rules
Read more about English grammar books PDF on e-grammar.org.
Be able to exercises
For pre-intermediate to advanced levels.
Be able to Exercise 1 Learn to use 'be able to' in all tenses.
Can - Be able to Exercise 2 Practice the difference.
Could - Would be able to Exercise 3 Make conditional forms (could - would be able to, could have been - would have been able to).
Be able to PDF worksheets
Free PDF exercises with answers to download.
- Complete sentences in all tenses.
- Choose correct options.
- Rewrite sentences and keep the same meaning.
Be allowed to Learn the difference between be able to a be allowed to.
PDF grammar rules:
English grammar PDF All PDF grammar rules on this website.
Be able to
Grammar rules with examples
Be able to is used to express ability to do something. (I was able to swim when I was five.) It is sometimes possible to use the modal verb can, but only in the present tense (I can speak English.), in the past tense (I could swim when I was five.) and in the conditional tense (I could try it if you helped me.).
Present tense: I am able, you are able, he is able
Past tense: I was able, you were able, he was able
Future tense: I will be able
Present perfect: I have been able, he has been able
Past perfect: I had been able
Future perfect: I will have been able
Questions and negative forms are made in the following way.
Questions: Are you able? Were you able? Has she been able?
Negative questions: Are you not able? (Aren't you able?) Has she not been able? (Hasn't she been able)?
Negative statements: I am not able, You were not able, We have not been able
It is possible to use be able to if we talk about a general ability in the present, but can is more common.
Eve can sing very well.
Eve is able to sing very well.
We can use was/were able to or could to talk about a general ability in the past.
Terry could speak German and French at primary school.
Terry was able to speak German and French at primary school.
Could is not used to talk about a specific event (one particular action). We must use was/were able to.
Terry was able to play football on Sunday because he wasn't injured.
This rule, however, does not apply to negatives and verbs of senses or thinking. In these cases both forms are possible.
We couldn't find your address.
We weren't able to find your address.
I could hear the noise.
I was able to hear the noise.
She could understand it.
She was able to understand it.
To talk about a future ability, we use will be able to. Can is not used for future actions.
She will be able to work next week.
If we speculate about an ability in the present or future, we use either could or would be able to.
I could live in London, I think.
I would be able to live in London, I think.
Could you come tomorrow?
Would you be able to come tomorrow?
If we speculate about an ability in the past, we usually use could + perfect infinitive (could have gone), even if would have been able to is also possible.
If Terry hadn't been injured, he could have played football.
If Terry hadn't been injured, he would have been able to play football.
In all other cases we must use be able to.
I have never been able to type.
I like being able to drive.
I'd love to be able to communicate in English.
Be able for possibility
Can is used in the present or future to express possibility.
The shop is closed. We can't go there.
The shop will be closed. We can't go there.
Could is used in the past.
You could meet her yesterday.
Be able to is used with all other tenses.
We haven't been able to go to the shop since it was closed.
We had been able to meet her before she fell ill.