What's the difference?

Is there any difference between MAY and MIGHT? They seem to be used to mean the same thing.

 

For many, they do. But it was not always the case. But today many linguists are quite happy to accept that these two words can be used to mean the same thing, as in the meaning 'it is possible'. However, there are examples where the two words do appear to be clear in their differences as regards permission and possibility, and in the area of historical context.

 

First, we will look at the meanings we all know. May and might are both used to suggest possibility: It may rain this afternoon, or it might rain this afternoon. However, may is used when it comes to permission: May I open the window? Yes, you may, although I have heard Might I open the window used for the same meaning.

 

In grammar terms, might is regarded as the past tense of may: I may do this task. He said he might do this task. 

In negative modal verbs, may not suggests no permission; You may not open the window! (There is a rule that says this is not permitted). Might not suggests it is not possible: You might not open the window! (It may be difficult to open for some reason.)

 

Now look at these examples:

 

The Queen may have married other several suitors before she met Prince Philip.

The Queen might have married other several suitors before she met Prince Philip.

(From English: History, Diversity and Change - pp.368-369, 1996)

 

The first example with may suggests that there was the possibility that the Queen had, in fact, married other men before she met Prince Philip, but we know she did not. This suggests a strong possibility, which we know is wrong.

 

The second suggests that the Queen might have married other men - that is, it was possible other men were available to marry the Queen, and not Prince Philip - if circumstances had been different, but we know she did not.

 

Here are some simplified examples:

 

I may have done this. (You don't know if I have done this and you can't be sure - this is only a possibility)

I might have done this. (I didn't, but it was certainly possible that I could.)

 

Oh no! I may have left my wallet at the restaurant! (You do not have your wallet now, and you begin to consider the possibility that you left it at the restaurant)

I might have left my wallet in the restaurant if you hadn't told me to put it in my pocket! (But I have my wallet now, and thankfully you reminded me to put it in my pocket.)

 

You might not see the Queen if you stand there. (It is possible that you may not be in the right place to see her.)

You may not see the Queen if you stand there. (It is not allowed; there is some official rule about your standing position that does not allow you to see her!)

 

But perhaps the best example of what appears to be a clear difference comes from a book review made in the Observer newspaper (which I have quoted [but rewritten for the benefit of our language students] via Oliver Kamm's book, Accidence Will Happen, page 215):

 

'...Hitler made up military strategy as he went along and may have lost the war because of these tactics.' (It is possible that what Hitler did was the reason the Nazis lost the war: this is an open historical question about what could have happened.)

 

'If the Germans had reacted quickly, they might have stopped the Allied invasion.' (But they did not, and this is a historical fact.)

 

Indeed, Kamm points out that the difference between may and might could matter when it comes to discussions about history. It also works with the other examples too. Try this one:

 

I may have said something bad because I was angry with her. But there's no excuse that If I hadn't been angry, I might have saved our marriage. (The speaker is talking about things he perhaps said to his wife while angry, which did not help his relationship, but cannot remember. But being angry was enough to make sure that she had had enough and that he will soon be getting divorced.)