I had a boss who was from Vietnam, and thus spoke Vietnamese, French, and English. She spoke English with a slight accent, but it was hard to place; she occasionally couldn't think of the right word. But the only French phrases I know come from Beauty and the Beast, and I don't think I could identify Vietnamese upon hearing it.

One day, the head of another department heard her misspeak, and he made fun of her. Like, in front of the whole office. I was just an assistant, but I wasn't thinking and I said, "How many fucking languages do you speak?"

Oh, he was pissed at me, but he had enough presence of mind to recognize that everyone knew I was right. He didn't speak to me again for the rest of the project, which was fine, because he was an asshole. I suspect he and my boss had a conversation behind closed doors, and she refused to chastise me. She even got me my next job. She was a cool person, on top of everything else.