While I was a student in Bergen, I got a summer job in a bakery. One of my tasks was to put the unbaked loaves onto planks and place them in the oven to bake.
The planks were ancient and worn with use, and one day I managed to get a splinter under my fingernail. I was trying to remove it when one of the bakers noticed me chewing at my finger and asked me what was the matter. I thought I knew the word for splinter in Norwegian, but unfortunately - unknown to me - there was a letter missing in my version, and the conversation (in Norwegian of course) went something like this:
Baker: What is the matter?
Me: I have got a fart under my nail.
Baker: Stop scratching your bum, then.
I understood what he had said, but could not for the life in me fathom why he said it. Fortunately, I had a date with Astrid (now my wife) that evening, and she explained the mistake that I had made.
If anyone out there is learning Norwegian from scratch, here are two more or less useful words:
flis = splinter (or tile)
fis = fart