An example of what I mean:
I, in China, told an English speaking Chinese friend I needed to stop off in the bathroom to “take a shit.”
He looked appalled and after I asked why he had that look, he asked what I was going to do with someone’s shit.
I had not laughed so hard in a while, and it totally makes sense.
I explained it was an expression for pooping, and he comes back with, “wouldn’t that be giving a shit?”
I then got to explain that to give a shit means you care and I realized how fucked some of our expressions are.
What misunderstandings made you laugh?
In Spain, my first real long-term girlfriend. American. We are visiting some of my relatives. She speaks passable Spanish. My aunt ask her something. She replies that she’s embarrassed, but she uses a “false -friend”, Embarazada, which means pregnant in Spanish. Me knowing what was going on, let the thing run for a bit. When explanations came there was a hilarious bit of manga size eyes and laughs.