May, might and could are really useful English modal verbs. We use them in lots of different ways but an important one how we use them to express uncertainty when we’re not sure.

You can use may might and could with the same simple structure if you’re talking about the present or the future. They mean the same thing and you’ll have no problems.

But do you know how to use them in the negative? That’s where it gets tricky. May not and might not don’t mean the same as could not (or couldn’t). Learn an important difference between may not, might not and couldn’t in this video.

This is an English grammar lesson with a twist. We’ll also tell you a story – a creepy story. Get ready to be scared!

Learn about how to use can and may to talk about permission here.
Learn more about can, could and be able to here.
See more grammar lessons here.

How to use may, might and could to talk about possibilities (1)

Hi. I’m Vicki and welcome to the first of two videos about how to use the verbs ‘may’, ‘might’ and ‘could’ to talk about possibilities. We’re also going to tell you a story. A strange and creepy story. You’ll love it.
There are two main ways we use modal verbs in English. One is when we want to try to control the world and what people do. For example, we can use modal verbs to talk about permission. We’ve made another video about that and I’ll put a link here.
And the other way we use modal verbs is to express our attitude and opinions. So for example, if we want to say we’re not certain, we often use these modal verbs. They’re really useful when we want to talk about possibilities.
So permission – possibility. Modal verbs often have more than one meaning. In today’s lesson you’ll learn how we use these three modal verbs to talk about possibilities.
Let’s see them in action.

Oh. Sit Carter. Good boy.
Hello everyone. Jay here. I’m traveling on business this week. This hotel is very old. It might be two hundred years old. Or three hundred? I don’t know but it’s dark and cold…. and there’s a strange smell in this room. It may be the kitchen downstairs. It could be cabbage. I’m not sure. I didn’t want to stay in this hotel but it’s the only place that would take Carter. Such a good boy. I didn’t want to leave him at home.
Anyway, I’m going to stop now and take Carter for a walk. It’s windy tonight and it could rain soon. I hope not because we might get wet. And then after our walkk, we may just go to bed and have an early night. I’ll speak to you all tomorrow.

Did you hear Jay say ‘may’, ‘might’ and ‘could’? He used them all to talk about possibilities, and they express the idea that we’re not certain. We use them when we don’t know something for sure.

This hotel might be two hundred years old. Or three hundred?
It may be the kitchen downstairs.
It could be cabbage. I’m not sure.

Could, may and might mean the same thing here, it doesn’t matter which word you use. They all indicate you’re not certain.
We can use them to talk about the present, and also to talk about the future. The structure is exactly the same.
So how can we tell if someone’s talking about the present or the future? Well, it doesn’t matter normally. We look at the situation and the context and we know. And if it’s important to be clear we can use adverbs or time expressions.

It could rain soon.
After that, I may just go to bed.

So if you’re not sure if something’s true now, or not sure if it will happen in the future, use may, might or could.
Now what about negative sentences? What if we think something might not be true, or we think things might not happen. Let’s hear some examples and see Jay is getting on.

Hello everyone. Well we’re still here but we might not stay in this hotel for long. Last night was terrible. The window in this room was rattling. It was so noisy we couldn’t sleep.
This morning I got up and I slammed the it shut. But it may not work. I think it might rattle again tonight.
I’ve asked the hotel if we can change our room. They’re going to try but they don’t have many rooms so they might not be able to help.
But the worst thing last night was I had a nightmare. I dreamed there was a young girl at the end of my bed and she wanted to kill me. I couldn’t see her very clearly because it was dark and she was hiding he face. But I knew she was evil and I was terrified. I may not be able to sleep tonight.
Carter doesn’t like this hotel either. He’s behaving very strangely. He keeps staring at the door like someone is outside. But when I open it and look, nobody’s there. It’s really weird. Carter may not sleep tonight either.

Poor Jay, and poor Carter. Let’s look at some of the things Jay said. He used the negative form of may and the negative form of might.

We might not stay in this hotel for long.
I’ve slammed the window shut but it may not work.
The hotel might not be able to help.
I may not be able to sleep tonight.
And Carter may not sleep tonight either.

With modal verbs we use ‘not’ to form the negative. Did Jay use contractions here? No. He didn’t say mayn’t of mightn’t. With may and might, say may not or might not.
OK, now what about could? Well, could is different in several ways. Let’s see what Jay said.

It was so noisy we couldn’t sleep.
I couldn’t see her very clearly because it was dark.

Did Jay use a contraction? Yes, we generally say couldn’t. Could not – couldn’t.
But something else is different here and this is important. The meaning is different to may not and might not. Have a look. Is he talking about present and future possibilities here? NO! He’s talking about that past, and things that didn’t happen. They wanted to sleep but it was impossible. He wanted to see the girl but it was too dark.
So here’s the thing. We use may not and might not to talk about things we’re not sure about, but couldn’t means something different. We use it to talk about things that didn’t happen in the past. We know they didn’t happen so there’s no uncertainty. So if you’re not sure and you’re feeling uncertain, don’t use couldn’t. It’s not the same as ‘may not’ and ‘might not.’
So let’s summarise. When you want to talk about possibilities, use could, may and might. They all mean the same thing and we use them all to talk about things that are possibly true now and things that will possibly happen in the future.
If you think things are possibly NOT true or NOT certain, say ‘might not’ or ‘may not’.
Don’t say ‘could not’ or ‘couldn’t’. We use that to talk about impossible things.
Great. Now you know how to use these modal verbs to talk about the present and the future. But what about the past? Come back next week and we’ll show you how to do that. But before we stop, let’s see how Jay and Carter are getting on?

Well as you can see, I couldn’t change our hotel room so Carter and I are still here. Carter’s not happy. He’s not eating much and he seems nervous. The phone rang everal times last night and he went crazy. I don’t know who called. I couldn’t hear very well because Carter was barking. But it sounded like a young girl’s voice. She didn’t say anything but she was laughing. Or could be she was crying. I’m not sure. Do you think this hotel could be haunted?
What do you think? Might it be haunted?

And what might happen to Jay and Carter next week?
Write and tell us in the comments. Please share this video with your friends, and see you all next week for part two of the story. Bye.

Learn about how to use can and may to talk about permission here.
Learn more about can, could and be able to here.
See more grammar lessons here.