Question from English4.today member Mahesh in India:

What is the difference between ‘would’ and ‘could’?

Hi Mahesh. This is a very common question and there seems to be a lot of confusion about what the difference is exactly between ‘would’ and ‘could’.

Answer

Let’s take a look at ‘would’ first:

‘Would’ for Unreal, Impossible or Hypothetical Situations

We probably see this most often in conditional sentences where we want to talk about a situation that is either not real or not likely to occur now or in the future. To do this we use a past tense of the verb in the if-clause and would + infinitive in the main clause. Have a look at these examples:

* If I knew how to speak French, I would visit France.* If she travelled by train, she would arrive this afternoon.

Contracting ‘Would’

Don’t forget that you can contract ‘would’ and that you will often see it as:

* I’d like to visit her. (= I would like to visit her).* They’d swim more often. (= They would swim more often)

‘Would Like’: Expressing a Desire for Something

OK.. that covers ‘would’ when we are talking about hypothetical situations but what if I say:

* I’d like a cup of tea, please. (= I would like …)* She’d like a Tomato Salad. (= She would like …)

Here, ‘would‘ is used as an auxiliary for the verb ‘to like‘ and takes on a special function of expressing desire for something. Notice that you cannot use ‘could‘ in this way.

‘Would Have’ to talk about something in the past that did not happen

Now, if we want to talk about something in the past that did not happen, we use had + past participle in the if clause and would have in the main clause. Look at these examples:

* If Simon had taken his passport, he wouldn’t have had a problem buying his ticket.* If Jenny and Max had remembered Mary’s birthday, she wouldn’t have been angry.* If I had lived in Australia I would have learned how to surf.

Hope your staying with this Mahesh – it’s a long posting as it has to cover quite a bit of territory so that you can really see where the differences are!

Now, lets look at ‘could’.

Could: Permission, requesting and expressing ability

We can use ‘could‘ to ask for permission, to express a possibility, make a request or express an ability to do something. Look at these examples:

* Could I borrow your car this evening? Mine is being repaired.* You could take the train. Then you won’t have any problems parking.* Yes, I could but I don’t know where the train station is.* Jonas could play the violin very well by the age of five.

‘Could Have’ to talk about hypothetical actions in the past that did not happen.

Until now I think the distinct usages of ‘would’ and ‘could’ have been pretty clear but here, with ‘could have‘ I’m afraid we are moving into an area where ‘could have’ and ‘would have‘ are very similar!

Like would have, (and should have … which we are not covering in this posting), could have can be used to talk about past hypothetical actions – things we did not do or other did not do or didn’t succeed in doing. For example:

* I could have gone to university if I had had better results at school.* I would have gone to university if I had had better results at school.

Now,