What are you talking about? A pretty common interaction is: Me: Can I have a coke? Waiter: Is pepsi okay? Me: That's fine Waiter: brings a Pepsi It seems

What are you talking about? A pretty common interaction is: Me: Can I have a coke? Waiter: Is pepsi okay? Me: That's fine Waiter: brings a Pepsi It seems that the above commentor doesn't have this exchange but instead silently substitutes.