Can / Be Able To

Modal Verbs

Group of Women
Asking about Abiliities. Getty Images / Hero Images

'Can' and 'Be able to' are both used to speak about abilities, and the possibility of doing something. 'Can' and 'Be able to' are known as modal verbs in English.

Here are some examples of 'can' and 'be able to' used to speak about abilities.

Can for Abilities

  • She can play tennis.
  • They could speak English at a very young age.
  • Peter can type 100 words per minute.

Be Able to for Abilities

  • My sister is able to run a marathon.
  • The students were able to get an A on the test.
  • We will be able to attend the class next semester.

Here are examples of the two forms to speak about possibilities.

Can for Possibilities

  • Can you come to the party next week?
  • Do you think he can help with my homework?
  • Peter told me he could pick you up at the airport.

Be Able to for Possibilities

  • We weren't able to get tickets to the concert.
  • She'll be able to study for the test tomorrow.
  • Jack won't be able to come for another three days.

Listed below are examples and explanations for can/could/be able to for ability and permission in the past, present. and future.

ExamplesUsage

He can play tennis well.
She is able to speak five languages.
They can come on Friday.
Jack will be able to come next week.

Use 'can' or 'be able to' to express an ability or possibility

NOTE: The future of 'be able to' is 'will be able to

He could swim when he was five.

Could in the past means the general ability to do something.

They were able to get tickets for the concert.

I was able to finish before 6.

I couldn't come last night, sorry. OR I wasn't able to come last night, sorry.

IMPORTANT: If someone was in the position to do something, or managed to do something, we use 'was/were able to instead of 'could'

In the negative,' wasn't able to' OR 'couldn't' are both correct.

 

Note: 'Can' is also often used to ask for permission, as well as 'may':

Can I come with you? = May I come with you?

Practice Can/Be Able To

Practice 'can' and 'be ale to' with this role play. Once you've finished, make up some of your own dialogues and practice with a classmate or a friend. 

Peter: Hi Janet.

Can you help me for a moment?
Janet: Sure, what's up?

Peter: I'm not able to understand this math problem. 
Janet: Really. I think I can help, but I'm not that good at math.

Peter: You were able to all the problems last semester, weren't you?
Janet: Yes, that's right, but I can't do everything. Let me see. 

Peter: Here you go.
Janet: Interesting, are you sure you're not able to do this?

Peter: Yes, that's why I'm asking for help!
Janet: OK. After I explain this, you'll be able to do without any problems.

Peter: Great. So what's the answer?!
Janet: Don't be in a hurry. Can I have a few minutes to think?

Peter: Of course you can. Sorry. 
Janet: No problem.