A Griceian bagel

Ran Ari-Gur:

"I've frequently run into this sort of problem at Burger King. A few different interactions are possible. The one that works out well is:

Me: I'd like a veggie burger combo.
Person behind counter (PBC): Would you like cheese on that?
Me: No, thank you.
PBC: O.K., your total is . . .

Another common interaction is:

Me: I'd like a veggie burger combo.
PBC: Would you like a medium, or a large?
Me: A medium, please.
PBC: O.K., your total is . . .

which I don't like so much, because "medium" is bigger and more expensive than what they give me when they don't ask. Eventually I decided that the question must be intended as "Would you like to upgrade that from the default size to either 'medium' or 'large'?", but the last time I went, the interaction I had was this:

Me: I'd like a veggie burger combo.
PBC: Would you like a medium, or a large?
Me: No, thanks.
PBC: Wait, so you don't want a combo? You just want the sandwich?
Me: Oh, um, I'll have a medium, please.

Not all of us have graduate degrees in the pragmatics of fast-food ordering."