CAN, COULD and BE ABLE TO - Part One

Are you ready for some English grammar?

I hope so!

We’ve had a lot of requests for a video about these three verbs.

There's a lot to cover so we're going to split this video into two parts.

And we'll show you, step by step, how to use them in English.

We're going to look at how we use these three words to talk about ability.

We also use 'can' and 'could' to make requests and ask for permission.

We have another video about that and I’ll put a link here.

But this is about ability and possibility.

Let’s start with the most common verb: 'can'.

We use it to talk about things we’re able to do because of knowledge or skills that

we have Si, digame, cuando?

Muy bien.

She can speak Spanish What are you doing?

I’m trying to whistle.

Oh I can do that.

It’s not just people that can do things.

Things can too.

Our old coffee maker was very small so we bought a new one.

This machine can make six big cups.

So we use 'can' to say what’s possible.

Can you fix it?

I’m not sure, but it might be possible.

Great.

The negative form of can is ‘can’t’ and we use it to say things are impossible.

I can't whistle.

Digame, cuando?

I can’t speak Spanish.

I can’t fix it.

You’ve probably seen the word 'cannot', where can and not are written as one word.

It’s a formal word and you’re more like to see it in written English.

We don’t usually say it.

We say 'can’t'.

'Can' is a modal verb.

We use it with the base form of other verbs – so the infinitive form, but without to.

There’s no 's' on the third person.

We don’t use 'do' to make questions.

We change the word order instead.

And we add 'not' to make the negative.

So 'can' is a special verb.

It doesn’t have an infinitive form.

It doesn’t have an -ing form.

And it doesn’t have a perfect form.

They just don’t exist.

When we want to use these forms, we use a different phrase – be able to.

It means the same thing as can.

So let’s look at these examples again.

‘Can’ and 'be able to’ are both possible here and they mean the same thing.

'Be able to’ is more formal and when we’re talking about knowing how to do something

like this, we generally say 'can'.

But there are some situations where it’s not grammatically possible.

Let’s look at some.

I can whistle.

I’d like to be able to whistle.

Notice Jay says 'be able to' here.

He doesn’t say ‘can’ because we don’t use infinitive forms with can.

Another example.

Mmm.

I love being able to have three cups of coffee in the morning.

Yeah, we’ve been able to make six big cups.

After 'I love' we need an -ing form.

But can has no -ing form so we say 'being able to'.

And can has no perfect form either so we say 'been able to'.

So when should you use 'can' and when should you use 'be able to'?

Well, normally you should use 'can'.

It’s what we generally say.

But sometimes it’s not grammatically possible.

When that happens, use 'be able to'.

Now we had a question from a viewer.

Bionexusgold said they always have a problem when they want to say 'can' for situations

that happened in the past.

Well yes, it’s tricky, Bionexus.

We can’t say 'canned', but perhaps you can guess what we say now.

We say 'was able to'.

This mouse is a problem.

I’ve ordered you a new one from Amazon.

Oh, thank you.

How much do I owe you?

Nothing.

I was able to log in with your password.

So 'was able to' is like the past tense of 'can'.

When you want to use 'can' to talk about a past situation, use 'was' or 'were able to'.

Were you able to fix it?

No sorry, I couldn’t.

Oh well.

Thanks for trying.

Notice Jay's answer here.

Could is another modal verb that we use to talk about past ability.

And the rules are a bit special.

So we're going to look at them in part two.

Come back next week and all will be explained.

Bye for now.