English grammar · A2-B1
Modal verb may: uses, structure and examples
Learn to express possibility, ask permission formally and infer what possibly happened without confusing may with might, can, should or would.
Practise may step by stepWhat may means and why context matters
May does not describe an action by itself; it changes how the following verb is understood. It can mark an uncertain possibility or formal permission, so its meaning comes from the speaker’s intention and the situation.
Like other modal verbs, may takes no -s with he, she or it, uses no to before the main verb, and does not need do for questions or negatives. Its stable form lets you focus on meaning.
How to form affirmative, negative and question sentences with may
May has a fixed position. The subject changes, while may and the main verb stay in their base forms.
Affirmative
subject + may + base verb
Negative
subject + may not + base verb
Permission question
May + subject + base verb?
Past possibility
subject + may have + past participle
- May is the same with every subject.
- Use a base verb without to after may.
- May not can mark negative possibility or formal prohibition.
- In permission questions, put may before the subject.
Possibility now or later
subject + may + base verb
Use may when you think something is possible but do not state it as a fact. The same pattern works for present and future situations; context or a time expression identifies the time.
A possible event after lunch.
Formal permission
May + subject + base verb?
May I…? is a clear, polite way to ask permission. It usually sounds more formal than Can I…?, which makes it useful in classrooms, interviews, customer service and deferential situations.
A formal request for permission.
Past inference
subject + may have + past participle
When you are not certain what happened, use subject + may have + past participle. May supplies uncertainty; have + participle places the guess in the past.
Missing the train is a possible past explanation.
May for present and future possibility
Use may when you think something is possible but do not state it as a fact. The same pattern works for present and future situations; context or a time expression identifies the time.
Do not turn may and might into fixed percentages. Both can work in many contexts, and the nuance depends on register, speaker distance and variety of English. This page teaches may; the detailed comparison belongs to its dedicated lesson.
A possible event after lunch.
Maya’s later arrival is possible.
May for asking, giving and refusing formal permission
May I…? is a clear, polite way to ask permission. It usually sounds more formal than Can I…?, which makes it useful in classrooms, interviews, customer service and deferential situations.
You can grant permission with Yes, you may or a full sentence. May not can refuse permission, although can’t is common in everyday speech. Context separates prohibition from negative possibility.
A formal request for permission.
Formal permission is granted until six.
May have + past participle for past possibility
When you are not certain what happened, use subject + may have + past participle. May supplies uncertainty; have + participle places the guess in the past.
The negative is may not have + past participle. It proposes a possible explanation without presenting it as established fact, which is useful in conversation and professional writing.
Missing the train is a possible past explanation.
Non-arrival is a possible past explanation.
Past possibility
subject + may have + past participle
Past inference
When you are not certain what happened, use subject + may have + past participle. May supplies uncertainty; have + participle places the guess in the past.
Missing the train is a possible past explanation.
Leo may have missed the train.
The two meanings of may not
She may not come means her arrival is uncertain. Visitors may not enter expresses a prohibition. The subject, situation and text type reveal the intended reading.
In rules, signs and notices, may not is often prohibitive. With predictions, plans or deductions, it usually marks negative possibility.
Negative possibility
Non-arrival is a possible past explanation.
Formal prohibition
Entry is not permitted.
May be or maybe: two different forms
May be contains the modal may plus the verb be. Maybe is an adverb meaning perhaps. Compare This may be true with Maybe this is true: similar message, different grammar.
A quick test: if perhaps can replace the word at the start of the sentence, use maybe. If a complement of be follows, use may be.
The key could be the correct one.
Perhaps this is the correct key.
May compared with might, can, should and would
Start with the communicative intention. This table defines boundaries; use the linked lessons for full comparisons.
| Modal | Core function | English example |
|---|---|---|
| may | specific possibility, formal permission or past inference | It may work. |
| might | more remote possibility, hypothesis or some reported-speech uses | It might work. |
| can | ability, general possibility or everyday permission | Can I leave? |
| should | advice or expectation, not mere possibility | You should rest. |
| would | hypothetical result, past habit or polite request | I would help. |
Common mistakes with may and how to fix them
These corrections target patterns. Remember modal + base verb and most errors disappear.
| Not this | Use this | Reason |
|---|---|---|
| He mays know. | He may know. | May never takes -s. |
| She may to leave. | She may leave. | Do not use to after may. |
| Do I may enter? | May I enter? | Invert may and the subject. |
| I don’t may go. | I may not go. | The negative does not use do. |
| This maybe true. | This may be true. | Here may is the modal and be is the verb. |
May exercises with immediate feedback
Choose by intention and structure. After answering, explain aloud why the other options fail.
Frequently asked questions about may
What does may mean in English?
Depending on context, may expresses possibility, formal permission or a possible inference about the past.
Which verb form follows may?
Use the base form without to: may go, may be, may arrive.
Can may refer to the past?
Yes. Use may have + past participle for past possibility: She may have forgotten.
What is the difference between may and might?
Both can express possibility. Nuance depends on context, register and speaker distance; universal probability percentages are misleading.
Is May I correct for asking permission?
Yes. May I…? is correct, formal and polite. Can I…? is more common in everyday conversation.
Continue along the route you actually need
Turn the rule into an automatic choice
Practise may in real situations and learn to choose a modal by the intention you want to convey, not by a memorised translation.