I don’t think that’s a separate meaning. It’s used as “may” because whether you are capable of doing something usually depends on whether you have the permission of the person you’re asking, which is why that usage is rediscovered over and over and over by speakers young and old. (Same phenomenon when you ask for food, “but” also want a container for it, and various other circumlocutions.)
“Can I have some cake?” --> “if I try to have cake, will you act in a way that prevents this?”
You coukd just as well be cheeky to the child that says, “May I have some cake?” by replying, “Yes, you are permitted to, but I will not get it off the shelf for you [and neither will anyone else and you can’t reach it].”
Where does it end? What word’s usage can you not narrowly interpret and criticize on that basis?
I don’t think that’s a separate meaning. It’s used as “may” because whether you are capable of doing something usually depends on whether you have the permission of the person you’re asking, which is why that usage is rediscovered over and over and over by speakers young and old. (Same phenomenon when you ask for food, “but” also want a container for it, and various other circumlocutions.)
“Can I have some cake?” --> “if I try to have cake, will you act in a way that prevents this?”
You coukd just as well be cheeky to the child that says, “May I have some cake?” by replying, “Yes, you are permitted to, but I will not get it off the shelf for you [and neither will anyone else and you can’t reach it].”
Where does it end? What word’s usage can you not narrowly interpret and criticize on that basis?