Use may for a higher-probability possibility or to ask/give permission (it may rain later; you may leave). Use might for a lower, more hypothetical or uncertain possibility (it might rain, but I doubt it).
The Core Difference
“May” expresses a reasonably likely possibility, or is used formally to ask for or grant permission: she may arrive late, may I ask a question?
“Might” expresses a weaker, more tentative or hypothetical possibility, and is also the past tense of “may” in reported speech: he might come, but it's unlikely, she said she might be late.
- stronger possibility / permission → may: it may rain; you may go
- weaker/hypothetical possibility → might: it might rain, but probably not
May and Might in Context
We may arrive a little late due to traffic.
It's unlikely, but she might still change her mind.
May I use your phone for a moment?
He said he might apply for the job.
The meeting may be postponed, though it might also go ahead as planned.
Common Mistakes
| Incorrect | Correct | Why |
|---|---|---|
| ✗ might I ask a question? (overly formal permission request) | ✓ may I ask a question? | permission, standard formal request |
| ✗ she may come, but it's very unlikely (weak possibility) | ✓ she might come, but it's very unlikely | weaker, hypothetical possibility |
| ✗ he said he may be late (in reported speech from past tense said) | ✓ he said he might be late | past reported speech of may |
| ✗ it might rain later, quite likely based on forecast | ✓ it may rain later | stronger likelihood |
| ✗ you might leave early today (granting permission) | ✓ you may leave early today | permission |
MAY = more likely / more formal permission. MIGHT = a Mightier degree of doubt — think of “might” as further from certainty than “may.”
Related Questions
- May vs Might — full confusing-words comparison page with additional examples and exercises.
- All Confusing Words — browse all 300+ word-pair guides.
- All Questions — more quick-answer pages.
- Grammar Quiz — test your knowledge of confusing word pairs.
Frequently Asked Questions
What is the core difference between may and might?
“May” suggests a somewhat likely possibility or is used for formal permission. “Might” suggests a weaker, more uncertain or hypothetical possibility.
Is might simply the past tense of may?
In reported speech, yes — “she may come” becomes “she said she might come” in the past. However, in present-tense standalone use, “might” also independently expresses a lower degree of probability than “may”.
Which is more polite for asking permission, may or might?
“May I...?” is the standard, polite, and slightly formal way to ask permission. “Might I...?” is even more formal and somewhat old-fashioned, often used in very polite or British formal contexts.
Can might be used for permission at all?
Rarely, and only in very formal, tentative requests (“Might I suggest an alternative?”), but “may” is by far the standard choice for permission in modern English.
Is there a real difference in probability between may and might?
Many grammarians argue “might” implies a slightly lower probability than “may”, though in casual modern usage, the two are often used interchangeably without a strict distinction in certainty.
Does might have not exist as a construction?
Yes — “might not” (or “mightn't”) expresses a negative possibility: “she might not come to the party.” “May not” also exists but can additionally express prohibition (“you may not enter”).
Is it correct to say I might have gone if...?
Yes — “might have + past participle” is the standard structure for expressing a hypothetical, unrealised past possibility: “I might have gone if I'd had time.”
Why do learners often mix up may and might?
Because both are modal verbs expressing possibility and are often interchangeable in casual speech, many learners do not realise there is a subtle degree-of-certainty distinction, or that “may” additionally covers formal permission while “might” does not.
Is “may as well” the same as “might as well”?
Both idioms mean that doing something is a reasonable choice given the circumstances, with nothing better on offer (“we might as well leave now”); “might as well” is more common in everyday speech, but “may as well” is equally correct.
Is there a difference between you may want to... and you might want to...?
Both are polite, softened ways to make a suggestion (“you may want to check that” / “you might want to check that”), but “might” often sounds slightly gentler and more tentative than “may” in this pattern, though both are acceptable in professional writing.