Ability and possibility

Can, could

I can speak three languages fluently.

Jenny can't come tonight. She's ill.

Our daughter could play the violin when she was three.

They couldn't wait because they were in a hurry.

Can is a modal verb. It only has a present form (which can be used with future meaning) and a past or conditional form (could).

For all other tenses and forms, we use be able to + infinitive.

We use be able to + infinitive for ability and possibility, especially where there is no form of can, e.g. present perfect, infinitive, gerund, future, etc.

We sometimes use be able to in the present and past (instead of can / could), usually if we want to be more formal.

Luke has been able to swim since he was three.

I'd like to be able to ski.

I love being able to stay in bed late on Sunday morning.

You'll be able to practise your English in London.

Fortunately, I am able to accept your invitation.

My colleagues weren't able to come to yesterday's meeting.

I’d love to be able to ski. 

I’d love to be able to ride a horse. 

We won’t be able to come.

We won’t be able to park. 

I’ve never been able to dance.

I’ve never been able to speak French.

She hates not being able to drive.

She hates not being able to cook.

Will you be able to find it?

Will you be able to afford it?

He’d love to be able to snowboard.

He’d love to be able to windsurf.

I love being able to understand everyone.

I love being able to speak to everyone.

They haven’t been able to finish.

They haven’t been able to come.

Exercise a

I've always wanted to be able to dance salsa.

My little boy wasn't able to speak until he was nearly two years old.

My little boy couldn't speak until he was nearly two years old.

She's much better after her operation. She'll be able to walk again soon.

He hasn't been able to mend my bike yet. He'll do it tomorrow.

It's the weekend at last! I love being able to go out with my friends.

When we lived on the coast, we used to be able to go to the beach every day.

I'm not able to send any email at the moment. My computer isn't working.

I can't send any email at the moment. My computer isn't working.

I was able to read before I started school.

I could read before I started school.

We won't be able to go on holiday this year because we need a new car.

Linda's pleased because she's finally been able to find a part-time job.

Alex is able to speak Portuguese fluently after living in Lisbon for ten years.

Alex can speak Portuguese fluently after living in Lisbon for ten years.

You are able to dance.

Are you able to dance?

You aren't able to dance.

I've been able to make sentences.

I'm being able to do it.

I'm able to be her husband.

I like being able to wake up late on the weekends.

I want to be able to wake up late on the weekends.

I'd like to be able to buy a Ferrari.

I might be able to come to your party.

I'd like to be able to speak English fluently.

I've never been able to play piano well.

I'd like to be able to do exercises three times a week.

I think young people should be able to speak English.

He's never been able to dance.

We won't be able to come.

She hates not being able to drive.