I'm outlining some examples that I have come across:
England... Burgers and patties, and burgers.
Everyone knows what a hamburger is, or often called simply 'a burger'. Well, not really. The Wikipedia description is 'a sandwich consisting of one or more cooked patties of ground meat, usually beef, placed inside a sliced bun' That's all good and well, until you go to where English comes from: England.
USA: What do you call that piece of meat inside of your burger?
England: A burger.
USA: So, you have a burger inside of your burger?
USA: Does the burger inside of your burger have a patty inside of it?
England: No, and what is a patty?
Very confusing, and then they'll tell you that they eat tea.
India... Metamorphosis involved in communication
Most countries have people saying things to other people, and then those people will reply to them. In India they have complex religious beliefs and rituals, and it seems to appear that they attempt to communicate with people who are likely reincarnated versions of themselves. This leaves the option open of reversing the reincarnation to communicate back to their former selves. Yeah, it's complicated.
India: The document you have requested is attached. Revert to me if you have any questions.
England: I have a question, but I don't think I evolved from being 'you' into being 'me' and I don't have the ability to reverse this evolution to be able to transform back into you. I suppose if I was able to turn back into you, I will also possess the answers you have. I think I am stuck with having to reply to you with a question instead.
Well, perhaps they are confusing the world 'revert' with the word 'reply'
South Africa... Goodbye, in the meantime
South Africans are aware of a lot of some of their common unique expressions, like 'howzit' and their word for traffic lights, which they call 'robots' However, many of them are not aware that the phrase 'so long' only means something similar to 'goodbye' to the rest of the world.
South Africa: Good day sir, table for two?
England: Yes, please.
South Africa: Smoking or non smoking?
England: Non smoking
South Africa: Here you go, would you like to order drinks so long while you look at the menu?
Now to Mr England above, it comes across like the following:
South Africa: Here you go, would you like to order drinks, Goodbye! while you look at the menu?