Would vs Could vs Should vs Might in English!



This is a question that pops up a lot in English learning.
What is the deal with Would vs Could and also Should vs Might?.

When should you use which one? Which is more polite? What would a native speaker say?

Don’t worry!

The following is your one-stop guide to the proper usage for each word. You can refer back to any of this during your independent study or you can ask a question in the comments and I’ll do my best to clear things up.


Probability vs Possibility

Before explaining the terms, we need to look at what these words are trying to explain.

Would vs Could = PROBABILITY

Should vs Might = POSSIBILITY

The best way to understand the difference is with the following sentences:

  • I will probably see you later. (more definite)
  • I will possibly see you later. (less definite – more doubt as it is also possible that I will not see you later)

Try to say them to yourself a few times before reading more so that you hear the difference. Got it? Great!


Would vs Could

The most important thing to realise here is that these verbs are being used to show probability.

It’s easier when you look at the root verbs of these words:

Would – Will

Could – Can


Would is more affirmative than could, but it requires conditions to be met:

  • I would go to the supermarket if Dad hadn’t taken the car.

Whereas with could, the speaker is able to perform the task but has an excuse as to why they won’t:

  • I could go to the supermarket, but I don’t feel like it right now.


Would and could can also be used for purposes of being polite when used in questions.

Would to a native speaker, sounds a little more direct than could.

Applying the root verbs above, if you ask someone to do something by saying:

  • Would you _____ ?

You are implying that they are definitely able to do it and therefore should have done it already.

Could sounds a little more polite because you are saying:

  • Are you able to do _____

This implies that you don’t expect them to do it but it would be great if they can.


Take a look at these two contrasting examples:

Spoken sentence: Would you close the door, please?

Translation: I know you are able to close the door, do it.


Spoken Sentence: Could you close the door, please?

Translation: If it is possible and if you want to, can you close the door please?


Realistically, a native speaker would not and should not get angry with you for using would rather than could, but this is one way to sound a bit more polite and less demanding.


Should vs Might

These two are very similar but are defining possibility which is slightly different from probability.


Let’s use the example of predicting the weather:

Spoken sentence: It should be raining now, but it’s actually sunny!

Translation: Rain was expected, but in fact it’s sunny.

In the example above, there was an 80 percent chance of rain.


Now compare that to the following:

Spoken sentence: It might rain later, but it also might be sunny.

Translation: Both events are possible.

In this instance, there is a 50 percent chance of rain, nobody is sure.



Should and might can also be used to explain obligation.

For example:

Spoken sentence: I should go to the bank later.

Translation: I have an appointment and I have some money to deposit.

There is a sense of obligation here. You could also say: I need to go to the bank later.


In comparison to the following example:

Spoken sentence: I might go to the bank later.

Translation: I don’t have to, but it’s possible that I will go to the bank.


Here is another example for practice:

Spoken sentence: I should go to work, but I don’t want to.

Translation: It’s a good idea for me to go to work and I probably will even though I don’t feel like it.


Spoken Sentence: I might go to work later.

Translation: I don’t have to go to work, but I could get some extra work done.


Yes, I know, this is a lot of information to digest!

The best way to completely understand the information is to practice by speaking to a native speaker so that it becomes natural. In any case, try saying it out loud and you will start to hear the difference between the examples.

I hope this helps and please feel free to ask any questions below!


Recommended for you:
Can vs Able To!
CAN or MAY? The difference between CAN and MAY!
Difference Between MAY, MIGHT, MAY HAVE And MIGHT HAVE!
Formal and Informal Email Phrases Starting with Greetings
Can vs Could vs Shall! – MyEnglishTeacher.eu

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