First off, when referring to possibility or probability, we tend to use the two words interchangeably, but if you speak to a Grammar Guru, they will tell you that a difference exists. And what is that difference? It's easy, really:
We use may when we want to express anything that is factual (or could be) or possible. We use might when we want to express something that is only improbable or hypothetical. Knowing that, then, how would you fill in the following examples?
Zoe and Talia go to Nebraska.If you're good at this, you'd answer may for the first four examples and might for the last three examples. And really, if you can keep in mind the fact that something ridiculous (or improbable) requires might, you'll be okay.
We leave for the store in five minutes.
Melina need to eat dinner soon.
Patty want to go outside.
If I color my hair red, I make myself Irish.
Aaron buy an $11,500 soccer ball if he wins the lottery.
They have made it to the game, if traffic hadn't been so backed up.
The problem, I think, is that might is the also the past tense of may. Yes, that's right! The English language at its finest.
So, if you want to say something that is factual, but in the past tense, then you need to use might. For example:
She might have stopped by the house at 3 p.m., but I was not there.Switching those verbs to the present tense could look like this:
He might have been caught cheating, but the teacher was not looking.
She may stop by my house at 3 p.m. but I will not be there.So anything else to trip us up? Yes, of course. What about if we're asking permission? Because both may and might can be used when asking permission, although may is more common.
He may be cheating, but the teacher is not looking.
You may have dessert.So it's okay to use both words, but what if you have previously asked the question, "May I go out with my friends?" You can answer that question in the following manner:
May I be excused?
Might I ask you for a favor?
Might I ask when class begins?
Might I ask you for a ride to campus?
I may go out with my friends.But that response can lead to confusion. Why? Because we want to know if you are not allowed to go out tonight or if you might not go out. Which is it?
At this point, you could be wondering if I remembered all of these details on my own and whether or not I call myself a Grammar Guru. I do not. I am far from a specialist in the grammar arena, but I do love the topic of correct grammar. I used my own knowledge plus a little help from some paper sources I found here in my pile of papers that didn't cite their sources.