My friend tried to call me a "night owl" because we tended to talk very late at night for my time zone. She accidentally called me a "lady of the night".

EDIT: "lady of the night" is a term for prostitute

Not my story, but one a friend told me.

Someone had the misconception that there was a huge, huge sector of labor dedicated to working in cemeteries in the USA. Like almost everyone knew at least one person who worked at a cemetery. This misconception arose due to the ubiquity of the term "graveyard shift" regardless of the actual job being performed.

I used to work with a Ukranian coworker, who had so little of an accent that I often forgot he was not a native English speaker.

One time during a meeting, I mentioned "there's more than one way to skin a cat" and I can still picture the horrified look on his face when he processed what I just said.

In all fairness, it's a pretty morbid expression!

Years ago, when I first moved to America from the UK, I was working in a pretty quiet office that backed on to a field. One day mouse appeared, freaked out a couple of the gals in the office, and then it ran and hid under an office cube.

I investigated to see where it was hiding, but it was pretty dark down there. So I asked if either of the gals had a torch. They both got an expression of wide-eyed horror, which confused me for a few seconds.

Then I realized that torch had a different term in America. So I corrected myself and asked if either of them had a flashlight. And they looked very relieved. They thought I was going to get an old school torch and try to smoke the mouse out or set it on fire, and probably set the whole cube on fire in the process.

Another friend once thought twat was a synonym of twit. First time she called someone a twat in my presence I was gobsmacked but thought I must have misheard; there was definitely nothing twattish going on.

The next time it happened I made a note to raise it privately with her later. "You do know what twat means don't you?" "Yeah, it's another word for twit." "Er, no."

I made this comment about a year ago: https://midwest.social/comment/6247683

"A friend of mine is a non-native English speaker. He teaches at an elementary school and works with ‘English as a second language’ students. He casually mentioned that he always tells his students to take a ‘horse bath’ in the bathroom sink after recess if needed. He was traumatized when I told him that he’d misheard that phrase for his entire adult life."

Chatting on Skype with a Chinese developer, he said "I need to take Friday off for family matters" and I said "no worries"

He apologized profusely, and eventually I realised that to him, "no worries" meant something like "No! I am very concerned!"

I've since taught them some more Australianisms.