Starlight, star bright
First star I see tonight
I wish I may, I wish I might
Have the wish I wish tonight.
American kids learn this nursery rhyme at an early age. But few think of it in terms of a grammar problem: what’s the difference between may and might?
Both are auxiliaries indicating modals — a category of verbs that express a mood, a wish, a hope or, in this case, a possibility. In spoken English, we tend to use them interchangeably. Since writing is more permanent than speech, it tends to be more formal, so it’s important to understand the difference and use the two correctly.
In general, may expresses a present possibility or likelihood:
I may go to the movies tonight. I haven’t decided, but it’s an option if I don’t get a better offer.
May also denotes permission: May I go now? (The difference between may and can is a whole different can of worms. That’s an idiom.)
Might is more hypothetical:
If weather conditions were right, it might snow tonight. But that’s not likely (or so we hope), which is why we use were instead of are.
It may indicate a suggestion:
If your professor thinks your writing needs help, you might consult the ESL coach.
Or it can indicate that a statement is contrary to fact:
I was very worried when you didn’t show up. You might have called. Meaning you could or should (also modals) have called. But you didn’t. You may have called means the speaker didn’t get the message.
In past tense there’s a difference between may have and might have. The former means it’s possible that something was true:
He didn’t tell me his plans, but he may have gone to the movies. This sentence speculates about a possibility. You don’t know if that’s where he actually went.
I might have gone to the movies if I didn’t have an assignment due tomorrow. But I do, so I didn’t.
Just might (not may) is a common idiom:
You might consult the ESL coach. (A suggestion.)
You know, I just might do that. (An affirmation.) Or: I just might.
Now, a quiz. Is this sentence from student work correct?
These gaps in Twitter might be one reason behind its limited success in Russia, which is experiencing a social media boom.
(Pause to think.)
No. In this case, may is more correct. It’s a serious possibility. Another quiz:
Greece might be kicked out of the Eurozone. Greece may go into more debt by taking yet another loan from Germany. Greece may face bankruptcy, impeachment and yet more austerity.
These are all real possibilities, and besides, this passage has three parallel clauses, so their wording needs to be parallel. Change might to may. The nursery rhyme, of course, dispenses with parallelism for the sake of the rhyme.
So here’s the wish I’ll wish tonight:
That everybody gets it right.