Or possibly nuits....
OK, I'll do it without the Ronnie Barker sketch! Mispronunciation of words and units
I was just taking screenshots of a new Guard colourscheme from Crytalking when I noticed (again) that the Kasrkin are Kasrkin and not Karskin. Any time I've seen them in White Dwarf I've been skim-reading it more and reading it as Karskin (pronounced more like Karrs-kin or Karr-skin, the elite kinsmen of Karr or something ) - partly because it's easier and partly because the spelling makes more sense! Then I saw it in DoW when making the Uber Painter and noticed that it was actually Kasrkin
The other one that I used to mispronounce (or get wrong) was Catachan (as in the Jungle Fighters). At first I thought it was Catchan (pronounced almost "Catchn")
So, anyone else misread any GW names and end up pronouncing them wrong for a while? And ones like Tzeentch don't count (silent T, like Tzar )