My previous question got me thinking about if/when the potential form or できる can be used to grant permission.
My doubts come about because I'm pretty sure that using the potential form/できる is never correct when seeking permission. Please correct me if I'm wrong.
You can take photos until 6 o'clock.
Does this only represent the ability to take photos e.g "we do not allow access after 6 o'clock so photography is not possible", "it gets dark after 6 o'clock so you can't take pictures"? Or can it signify permission as well i.e. "We allow you to take photos only until 6 o'clock"?
There seems to be a grey area where the ability to do something is taken away because permission has been removed (like the allowing access example above), which I guess is the reason that 'can' serves both purposes in English.
Sundowner's statement in my previous question, "Regarding できる, it sounds natural when it is talking about the speaker allowing someone to take pictures, e.g. in case of a zoo.", suggests that できる can indeed be used to grant permission. I wonder in what circumstances this would be preferred to something like 撮ってもいいです.