system
Given the following post, respond as if you're commenting on Reddit:
human
CMV: saying “may or may not” together is unnecessarily redundant. “May” and “may not” each separately imply that the opposite could be true, therefore you only need one of them!

I hear people say these types of phrases very frequently,
“I may or may not agree”,
“she may or may not help you”,
“I have a late meeting so I may or may not be there”
“This may or may not work”

I think this is totally redundant and not at all necessary.  I simply don’t think that you need both.

If I say, “I may not be there” it has the same effect as “I may be there”, I.e. both phrases imply that the opposite could be true, therefore you don’t need both.  I *do* think one has more of a positive feel to it vs the other having a more negative feel, but it also depends on the context.

Regardless of this, including both “may” and “may not” in the same phrase would negate the positive or negative feel that each of them would have, and including both just adds extra and unnecessary redundancy.

I’m totally willing to consider I’m wrong about this, but every time I hear someone say this, I cringe a little thinking to myself, “why say both?”
gpt
It is necessarily redundant.

You're correct that 'may' logically entails 'may not', and vice versa, so from a viewpoint of pure logical statements, saying both is redundant.

However, the point of communication isn't to make logically accurate statements. The point of communication is to accurately convey intended meaning to a listener.

And unfortunate, listeners are often imperfect.  It's a well established fact  in the cognitive science and communications literature that people don't estimate probabilities very precisely or reliably from short verbal descriptions, and they use verbal cues that go beyond the literal meaning of a sentence to make those estimates.

Saying something 'may be true' or 'may not be true' convey the exact same information, technically.  But someone who hears 'this may be true' probably thinks that it is, like, 90% likely to be true, and someone who hears 'this may not be true' probably thinks that it is 90% likely to not be true, because they're reading into the choice of words and framing that the speaker used (and this isn't always wrong,speakers*do* make those types of choices to convey relative certainty, beyond the literal meaning of the words).

So given that human listeners will interpret 'may' and 'may not' to mean different things, how do you communicate to them that the probability really is around 50/50, or that you really have no clue about the probability at all?  That's when you chose to say 'may or may not.'  Even though it still doesn't logically mean anything different form 'may' or 'may not' alone, the listener will casually interpret it to mean 50/50 or very high uncertainty; so if that's what you want to communicate to them, then that's what you should say.

So, it is *necessary* redundancy, to convey additional information beyond the literal meaning of the words.