The joy of being a PhD student in the midst of writing is that I have several people correcting my work. Several British
people. Northern to be specific. They'll give me quite a hard time when I lapse into American spelling ("what is this characteriZation? What's the zed doing there? What is this word?"). What I find is that they love to change my "while"s into "whilst"s!
We have this word, whilst, in America, I'm sure we do. I just don't think I've come across it in anything written since the turn of the century. It's so old-school sounding. People here use it all the time, in place of "while." Dictionary.com lists them both as conjuctions but with "while" as the Archaic one!
So who knows? I hear arguments all the time about which English is more correct, I tend to think it must be the British English, but I hear compelling reasoning American English too. I'm not a linguist or whomever would know this, do you?
And whilst we are at it, what's up with "Zed"? (#51) No one ever says, "zee." How did that come about?