My French skills were the cause of much hilarity this afternoon:
A colleague called to say that she was experiencing light bleeding during pregnancy and that she needs some time off. As my boss happened to walk into the room at that point, I passed her the phone with the remark "elle a le sang qui coule". I didn't understand why she suddenly went white, snatched the phone and shot out of the room.
I looked over at my French "room-mate" colleague, who had caught the whole situation and was killing herself laughing. She explained between gasps that I had painted a near death scenario ! Literally translated I had said: "her blood is flowing / she is loosing (a lot of) blood!"