Can we use "couldn't" to talk about future possibility?

[Mike MC]

Here's part of the book Focus on Grammar 5:



Can we use "couldn't" to talk about future possibility?

 

[Tarheel]

I wouldn't.

 

[BobK]

Here's part of the book Focus on Grammar 5:

View attachment 5842

Can't we use "couldn't" to talk about future possibility?

Why would you want to?

But, now I think of it, it would make sense in a case like this:
'I couldn't start at 8.00 because they had sent the wrong paper. It was gone 9.30 when the courier arrived with the right one.'

 

[Tarheel]

Why would you want to?

But, now I think of it, it would make sense in a case like this:
'I couldn't start at 8.00 because they had sent the wrong paper. It was gone 9.30 when the courier arrived with the right one.'

I don't see anything about the future there

 

[jutfrank]

Can we use "couldn't" to talk about future possibility?

Let's keep it simple: No.

 

[emsr2d2]

I'm inclined to go with jutfrank's simple "No" but you might hear it from native speakers. Imagine that Henry has been invited to two parties on the same evening. He's trying to decide which one to go to. He asks a friend what they think. They say "Well, if you went to Jane's party, you couldn't go to Stephen's and I think you'd enjoy that more". Technically, they should say "If you go to Jane's party, you wouldn't be able to go to Stephen's ..." but "couldn't" is possible there instead.

 

[BobK]

I don't see anything about the future there

Doh! [Note to self: read the question.]

 

[sitifan]

might, may, could​

We use might, may or could to say that we think something in the present or future is possible but we're not sure.

I might see you tomorrow if you're in the office.
There may be another issue that we don't know about.
This illness could be prevented.

They all have the same meaning, but may is more formal than might and could.

Adding well after the modal makes the situation sound more likely.

I'll try the pharmacy, but it might well be closed now.
She may well have to rethink her plan.
That could well be true.

The negative forms are may not and might not (or mightn't).

We may not need waterproof jackets, but I'll pack them anyway.
Safi might not come today as he has his driving test.

Couldn't is different from may not and might not. It means something is impossible.
https://learnenglish.britishcouncil.org/grammar/c1-grammar/modals-probability#:~:text=We use might, may or,This illness could be prevented.

 

[5jj]

This illness could be prevented.

That could well be true.

These are not very good examples of could being used for future possibility.

 

[Tarheel]

It could happen.

 

[sitifan]

It could happen.

What could happen?

 

[Tarheel]

What could happen?

It depends on the subject. It's using "could" to talk about the future. Somebody says, "What about XYZ?" Then I say, "It could happen." (It's a possibility.)

 

[BobK]

​

The negative forms are may not and might not (or mightn't).

In some old books, and in the speech of a dwindling number of old people, you may also (in BE) come across "mayn't".