Common mistakes
Can or may: ability, possibility, and permission
At the library desk, you might ask, Can I borrow this today? In a formal notice, you might read, Visitors may borrow two books. Both sentences concern permission, but their setting changes the choice.
Choose can for ability and ordinary permission, and choose may for possibility or more formal permission.
Read and practice
Read the examples and try the written questions in this guide. Listening recordings are not available for this lesson yet.
Try the written questions
can / may /kæn/ /meɪ/
The short answer
Use can for ability and usual spoken permission. Use may for possibility and for permission when the situation is formal or careful.
I can swim, but I may stay near the shore if the weather changes.
Why it works: Can describes the speaker's ability. May describes something that is possible later.
3 more examples
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Rina can solve the problem without help.
Can tells us that Rina has the ability to solve it.
Not this:Rina
may solvethe problem without help. What changes: May changes the meaning. It says that solving the problem is possible, but it does not say that Rina has the ability. -
The outdoor event may move indoors if it rains.
The move is possible, but nobody knows yet whether it will happen.
Not this:The outdoor event
can moveindoors if it rains. What changes: Can can be possible in this sentence when an indoor space is available, but may better highlights the uncertain decision. -
Can I leave my bag at the desk?
This is a normal request for permission in everyday speech.
Not this:
May I leavemy bag at the desk? What changes: The request is still for permission, but may sounds more formal and careful.
Read the full guide
First identify the meaning. If the sentence asks what someone is able to do, can is the usual choice. If it describes an uncertain future result, may is often the clearer word. Permission can use either word, depending on the tone.
Start with the meaning
A modal verb adds an idea to the main verb. Can often adds ability or ordinary permission. May often adds possibility or formal permission. The rest of the sentence tells you which meaning is needed.
I can type quickly, so I may finish the report before lunch.
Talk about ability
Choose can when someone has the skill or physical ability to do something. It works with present ability and general ability. May does not normally describe a learned skill.
Omar can read the map without his phone.
Omar can read the map describes his skill. Omar may read the map describes one possible future action.
Talk about possibility
Use may when you think something is possible but uncertain. You can say a package may arrive tomorrow or a meeting may take longer than planned. The speaker is not saying that the event will definitely happen.
The answer may be in the last email.
Can also describe general possibility. A delayed flight can cause missed connections means this is something that happens in some situations. May cause describes a particular possible result.
Ask for permission
In a classroom, shop, or conversation with friends, Can I...? is natural. It asks whether something is allowed. May I...? asks the same question with a more formal or respectful tone.
Can I charge my phone here?
May I speak to the manager, please?
Read rules carefully
Rules and notices often use may to give permission. Visitors may take photographs means photographs are allowed. A rule that says visitors may not take photographs means they are not allowed to do so.
Students may use a dictionary during this part of the test.
You may not enter can mean entry is prohibited. You might not enter means it is possible that you will choose not to enter.
Choose in context
A receptionist says that a visitor is allowed to wait in the lobby. Which modal fits a formal sentence: can or may?
Use may: The visitor may wait in the lobby. In a relaxed conversation, the receptionist could also say, You can wait in the lobby.
Before you go
Remember this
Use can for ability and everyday permission. Use may for an uncertain possibility and for formal permission. Check whether the sentence asks about skill, chance, or permission before choosing the modal.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
Try the written questionsListening test not available yet
This lesson does not have the recordings needed for a listening test. Use the written questions in the guide to check your understanding.
Try the written questionsQuestions about "Can or may: ability, possibility, and permission"
What is the difference between can and may?
Can usually expresses ability or ordinary permission. May usually expresses possibility, and it can give or request permission in a more formal style.
Rina can solve the problem without help.
Can I use can to ask for permission?
Yes. Can I...? is a normal way to ask for permission in everyday English. May I...? has the same basic purpose but sounds more formal or careful.
Rina may solve the problem without help.
Why is may not sometimes confusing?
In formal rules, may not often means that something is forbidden. In other contexts, may not can mean that something is possibly untrue or might not happen, so context matters.
The outdoor event may move indoors if it rains.
Can may describe ability?
May does not normally describe a person's skill or ability. Say She can drive or They can speak Spanish when you mean that somebody has the ability to do something.
The outdoor event can move indoors if it rains.
Can can describe possibility?
Yes. Can often describes general possibility, as in Winter can be cold here. May is more useful when you mean one uncertain event or result.
Can I leave my bag at the desk?
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