Look at these examples to see how must, might, may, could and can't can be used.
That must be the main entrance. I can see people queuing to get in.
I've lost my keys. They might be at work or they could be in the car.
You can't be bored already! You've only been here five minutes.
Try this exercise to test your grammar.
- Grammar test 1
Read the explanation to learn more.
Grammar explanation
We can use modal verbs for deduction – guessing if something is true using the available information. The modal verb we choose shows how certain we are about the possibility. This page focuses on making deductions about the present or future.
must
We use must when we feel sure that something is true or it's the only realistic possibility.
This must be her house. I can see her car in the garage.
He must live near here because he always walks to work.
Come inside and get warm. You must be freezing out there!
might, may, could
We use might, may or could to say that we think something is possible but we're not sure.
She's not here yet. She might be stuck in traffic.
He's not answering. He could be in class.
We regret to inform you that some services may be delayed due to the bad weather.
They all have the same meaning, but may is more formal than might and could.
can't
We use can't when we feel sure that something is not possible.
It can't be far now. We've been driving for hours.
She can't know about the complaint. She's promoted him to team leader.
It can't be easy for him, looking after three kids on his own.
Note that these verbs, like all modal verbs, are followed by an infinitive without to.
Do this exercise to test your grammar again.
- Grammar test 2
Dear sir.
Do we use modal verbs+perfect infinitives to express past possibility only or to show past imaginary situation?
If not, then what are other usages of such forms(modal verbs with perfect infinitives)?
Thanks.
Hello sartaj,
Modal verbs have many uses depending on the context. Past possibility is only one of these. Please look at our pages on modal verbs for more information.
https://learnenglish.britishcouncil.org/grammar/english-grammar-reference/modal-verbs
Peter
The LearnEnglish Team
Thanks dear sir.
Please answer my question written below:
1.What is the difference between two sentences written below-
"I think he might be busy.
And
I thought he might be busy."
"I think she should have asked them.
And
I thought she should have asked them"
Thank you.
Hello sartaj,
In each pair of sentences the difference is the time of thinking:
I think he might.... > this is what you think now (in the present).
I thought he might... > this is what you thought then (in the past); you may have changed your mind since then.
Peter
The LearnEnglish Team
Thank you so much dear sir.
Please tell me what's the difference between sentences below?
1.You should have done that.
2.You could have done that.
3.You might have done that.
4.You would have done that.
Hello sartaj,
Please first try to answer the question yourself. Tell us what you think and we'll tell you if you're on the right lines or not.
Peter
The LearnEnglish Team
Dear teacher,i just want to know that all those sentences are possible in different ways?
Hello sartaj,
I understand but please remember that we're a small team here trying to answer questions from thousands of users. It's not possible for us to provide long explanations of multiple sentences like this, or to provide answer after answer on the same topic. We can answer concrete questions about particular aspects of the language but this kind of question goes beyond that.
All of the sentences are grammatically possible. I think the information on our various pages about modal verbs explains the differences in some detail - please read through those page and I think you'll find the information and examples you need.
Peter
The LearnEnglish Team
Ok dear teacher. Thanks.
Please answer this question.
She could speak several languages.
I read above sentence on your website.Does this sentence mean that she can't speak several languages now? Does this sentence talk about the past?
Please explain this?
Hello dear teachers👋
The sentences written below have the same meaning?Can we use these sentences interchangeably?
1.John may be angry with you.
Or I think John is angry with you.
2.The children might be playing outside.
Or Maybe/perhaps the children are playing outside.
3.There might be a dog in that house.
Or I am guessing that there is a dog in that house.
Thanks.