may vs might

[CHJR]

How is it no one in this country (perhaps no one in the world?) seems to realise the past tense of "may" is "might"?

To whit: He says he may go tomorrow. He said he might go tomorrow.

Do you mean 'why"?

That too, demented

Technically "might" is the past of "may", in the same way that "should" is the past of "shall". Grammatically though, in almost all cases they are synonyms.

Your example is unclear though- what are you trying to say? There is nothing wrong with:

"He says he might go tomorrow" or indeed "He said he may go tomorrow".

In your example the two are synonyms and have no discernible difference other than that we'd probably use "might" more in that type of sentence than "may" which is seen as being more formal.

This is the danger with modals and the zealous over-application of the learned rule that indirect speech needs a back-stepped verb. Only at a very elementary level is that taught as an axiom. Once the nuances of language learning kick in, you quickly see that that isn't the case. In fact using the past tense of a modal in indirect sentences is quite idiomatic and much less formal than carrying on with "may". "Might" wouldn't be wrong as such, but you'd get some teachers red-penning it if it were an indirect speech exercise.

Might is also subjunctive. This is far more misused.

"The President said that if he hadn't sent in the army, the outcome may have been far worse."

ARGH. "May" means "could happen". When you're talking about an impossible hypothetical, it literally couldn't happen, so you can't and mustn't use "may".

I haven't heard that use MrsH. Is it American? It sounds American somehow. Though I suppose that's because Americans don't use "might" as much as "may" in other may/might contexts.
#modalmusingmonday

Nope, that's just grammar! I'm confident it isn't AmEng specific. It is fading out of common use though which is a shame because moods are very useful.