“A panda walks into a cafe. He orders a sandwich, eats it, then draws a gun and fires two shots in the air.
"Why?" asks the confused waiter, as the panda makes towards the exit. The panda produces a badly punctuated wildlife annual and tosses it over his shoulder.
"I'm a panda," he says, at the door. "Look it up."
The waiter turns to the relevant entry and, sure enough, finds an explanation.
Panda. Large black-and-white bear-like mammal, native to China. Eats, shoots and leaves.”
― Lynne Truss, Eats, Shoots & Leaves: The Zero Tolerance Approach to Punctuation
You see a panda walk into a bar, duck down on the floor and get to the nearest exit. They be cray cray.
So if the teacher had simply said, "yes," but in her head, she wasn't giving him permission, just stating that she believed he possessed the capability of entering, would he be able to enter or not?
My late gram too, every dam time: I don’t know young man, can you do a thing or may you? Why are you asking my permission about your ability to do stuff?
In Spanish, may and can are the same verb: poder. Asking ¿Puedo ir al baño? can mean both may I go as well as can I go. And if you wanted to be somewhat eloquent, it can also mean am I able to go