May vs. Might for Possibility and Permission

Use may or might to say something is possible. “The café may be closed” and “The café might be closed” both leave the answer open. May can also give permission. Might often fits imagined situations and reports of what someone said earlier.

May vs. might at a glance

Use either word for many present and future possibilities

“Dani may be in the studio” describes a possibility now. “Dani might be in the studio tomorrow” describes a possibility later. You can swap may and might in either sentence and keep the basic meaning. Some readers hear might as more tentative. The surrounding words and the situation do more to show how sure you are. For example, “The roads might close if the river rises” names the condition that matters. See the British Council’s guide to expressing probability.

Use the base form immediately after either modal. “The studio may close early” uses close. “The crew might be working late” uses be.

Use may have or might have to make a guess about the past

“Leah may have put the keys in her bag” and “Leah might have put the keys in her bag” are both guesses. The pattern is may or might, then have, then a past participle such as put, left, or forgotten.

Use might have for an imagined result

“If Leah had brought the key, we might have opened the storage room.” The if clause imagines a different past. It tells you that Leah did not bring the key. Might have opened gives one possible result in that imagined situation. See Washington State University’s usage note on may and might.

Might is common when you report may

If Leah said, “I may work late,” you can report it as “Leah said she might work late.” This shift in reported speech is called backshift. If Leah spoke earlier today and her plans are still open, you can keep may. “Leah said she may work late tonight.” See Cambridge on might in reported speech.

Use may to ask for or give formal permission

“May I enter?” asks for permission. “You may enter” grants it. “Might I ask a question?” is a very formal request. A natural answer is “Of course” or “Yes, you may.” Everyday permission often uses can. See Can vs. May.

May not can express uncertainty or a prohibition. In “The store may not open today,” it means the store might stay closed. In “Visitors may not enter the storage room,” it states a rule. If a reader could take either meaning, choose wording such as “The store might stay closed” or “Visitors must stay out of the storage room.”

Practice choosing may and might

1. Which statement describes both “The ferry may run late” and “The ferry might run late”?

   1. Both guarantee a delay.
   2. Both refer to a delay that already happened.
   3. Both express the possibility of a delay.
   4. Both grant permission to delay the ferry.

2. Which sentence grants a visitor permission to enter?

   1. You may enter now.
   2. You might enter later if the door opens.
   3. Might I enter now?
   4. The guide may arrive soon.

3. “Omar said, ‘I may arrive early.’” Which version reports that possibility with backshift?

   1. Omar said he may arrive early.
   2. Omar said he must arrive early.
   3. Omar said he might arrived early.
   4. Omar said he might arrive early.

4. Which sentence imagines a result in a past situation that did not happen?

   1. Tara might get a ride tomorrow.
   2. If Tara had called, I might have picked her up.
   3. Tara may have called. I’ll check my phone.
   4. Tara may call after work.

5. Which sentence uses may not to express uncertainty about the weather?

   1. Visitors may not bring food into the exhibit.
   2. Guests may not park in the loading zone.
   3. It may not snow tonight after all.
   4. Employees may not use the freight elevator.

Show answers and explanations

1. Possibility in both sentences

   1. Incorrect. A guarantee would commit to the outcome.
   2. Incorrect. The sentences look ahead to a possible delay.
   3. Correct. Either modal leaves open whether the ferry will be late.
   4. Incorrect. These sentences speculate about the ferry’s schedule.

2. Granting permission

   1. Correct. The speaker authorizes the visitor to enter now.
   2. Incorrect. The sentence gives a possible outcome.
   3. Incorrect. The speaker asks for permission.
   4. Incorrect. The speaker is uncertain about the guide’s arrival.

3. Reporting an earlier statement

   1. Incorrect. This keeps the original modal, which can work when the possibility still applies.
   2. Incorrect. Must changes the original meaning.
   3. Incorrect. After might, the verb takes the base form arrive.
   4. Correct. Might is the backshifted form of may here, and arrive is the base form.

4. An imagined past

   1. Incorrect. This concerns a future possibility.
   2. Correct. If Tara had called sets up an unreal past condition, and might have picked gives a possible result.
   3. Incorrect. This is a guess about what happened.
   4. Incorrect. This looks ahead to a possible call.

5. Interpreting may not

   1. Incorrect. The sentence states a rule about food.
   2. Incorrect. The sentence prohibits parking in a particular place.
   3. Correct. The forecast leaves open the possibility of an evening without snow.
   4. Incorrect. The sentence denies permission to use the elevator.

For a chart of the other helping verbs and their uses, see the guide to modal verbs. For more examples of imagined conditions, see the guide to conditional sentences.