Writers often run into trouble with using may or might. These words are modals, which combine with main verbs to suggest conditions like need, ability, probability, likelihood, and permission. Other modals include can, could, should, would, and must. May and might are problematic because there is such a subtle difference between the two.
In general, may is considered to be present tense while might is the past.
I may go to that concert.
I might have gone to that concert if it had been less expensive.
Might is also considered more tentative or less likely to happen than may.
May I have that book?
If I promise to return it promptly, might I have that book? (Tentative.)
I might stick my hand in that wasp’s nest if I decide it is a good idea. (But probably not.)
Sometimes may is used regarding having permission.
I may be able to use the corporate library.
This implies that you’re hoping for permission. However, if you’re unsure whether or not you’ll have time to use the library, use might.
When it comes to expressing possibility, may and might can be interchangeable.
They may arrive before midnight.
They might arrive before midnight.
They might have already arrived.
It gets more confusing when you’re trying to determine the likelihood of something happening.
I might write a best seller someday, but I may get a poem published next week.
The previous sentence suggests that publishing a poem is more likely than writing a best seller. If the outcome is likely, use may. Use might when the outcome is not certain.
One more example to help confuse, er, clarify things further:
A ferry crashes in the Seattle harbor. We don’t know how bad things are yet, but the captain may have been injured. A few hours later we find out that the captain is fine. He’s lucky. He might have been seriously injured. If not for the captain’s skill and experience, this might have been quite the disaster.
Worrisome words like may or might don’t have to throw a wrench in your writing. The proofreaders at Writer’s Relief are here to help!