“May” vs. “Might”: What’s the Difference?

May and might are pretty similar words: they both have to do with possibility and probability. However, these words have their differences. So what ARE those differences, and when do you need to be careful to not mix up the two?

What’s the Difference?

Here are the dictionary definitions of each word:

If that didn’t clear up your confusion about the differences between may and might, I don’t blame you one bit. To really understand how these words’ functions are distinct, we need to dive deeper into tense, likelihood, and reality.

Tense

Both may and might can be used in the present tense, but if the sentence is PAST tense, you almost always need might (not may).

INCORRECT: If I had remembered my grocery list, I may not have forgotten to buy eggs.

CORRECT: If I had remembered my grocery list, I might not have forgotten to buy eggs.

INCORRECT: I may have left the keys in the car, but at least no one stole it!

CORRECT: I might have left the keys in the car, but at least no one stole it!

Although this is more of a general rule (not a hard-and-fast one), it applies to most situations and is a good starting point for keeping these words straight!

INCORRECT: Gary stopped to check his mailbox for any notes that may have been left by Cindy.

CORRECT: Gary stopped to check his mailbox for any notes that might have been left by Cindy.

It’s easy enough to remember that might is the one to choose for past-tense situations, but how do you know which one to pick if your sentence isn’t past tense? It comes down to likelihood and reality.

Likelihood in Hypothetical Situations

When you’re talking about a hypothetical situation (may and might are very common words in such situations), you need to decide how likely it is that this situation will actually happen. If you think it is very likely to happen, you should use may; If you think it is NOT very likely to happen, use might.

May carries more likelihood: When the speaker uses this word, the audience can assume that the speaker thinks the even will probably happen. Might communicates more uncertainty.

We may go out to eat tonight, and we might try that new ramen restaurant down the road.

With this sentence, the speaker is communicating that it’s very likely that they’ll go out to eat, and it’s also possible (but less likely) that they’ll try the ramen restaurant.

Joseph may attend the concert, and he might even buy a t-shirt.

It’s on the speaker to decide just how likely it is that the situation will occur and choose either may or might accordingly. May means more likely and might means less likely, even though both express possibility.

Reality

Might can be used to discuss situations that WERE possible but did NOT occur. May cannot be used in this way.

INCORRECT: Philip may have won big, had he bet on his favorite horse.

CORRECT: Philip might have won big, had he bet on his favorite horse.

Philip COULD have won big, but he didn’t. This is discussing a possibility that is contrary to the actual fact. Because it’s not what really happened, we need to use might instead of may.

INCORRECT: If only Ursula could have controlled her temper, she may not have lost her job.

CORRECT: If only Ursula could have controlled her temper, she might not have lost her job.

In reality, Ursula DID lose both her temper and her job. Since we’re discussing a situation that is not reality, we need might.

Might Have vs. May Have

As was just discussed, might have is used to discuss counterfactual past events (i.e., events that didn’t actually happen). May have cannot be used in this way.

Sally might have won class president, had Julie not been running against her.

I might have forgotten to invite Lexie, had I not run into her at the store.

May have can be used to discuss past events when the outcome is unknown.

Sally may have won class president, but we won’t know until all the votes are counted.

I may have forgotten to invite Lexie; I need to text her to make sure.

If you KNOW the outcome and are discussing hypothetical outsomes that are NOT what actually happened, use might have. If you DON’T know what actually happened yet and are discussing possible outcomes, use may have.

What questions do you have about may versus might? Let me know in the comments!

Click here to learn the difference between comprise and compose.

Sources:

• “America’s Most Trusted Dictionary.” Merriam-Webster. Accessed August 7, 2024. https://www.merriam-webster.com/.
• Ebbitt, D. R., and W. R. Ebbitt. Index to English. 8th ed. New York: Oxford University Press, 1990.
• Einsohn, Amy. The Copyeditor’s Handbook. 3rd ed. Berkeley and Los Angeles, California: Univ of California Pr, 2011.
• Kramer, Lindsay. “‘May’ vs. ‘Might’: What’s the Difference?” Grammarly, March 28, 2023. https://www.grammarly.com/blog/commonly-confused-words/may-might/.
• Merriam-Webster. Merriam-Webster’s Dictionary of English Usage. 14th ed. Taunton, MA: QuadGraphics, 2016.