What is the most often...

I agree that most errors in spelling are a bit lazy...that said, I would think that a lot of the errors are simply the fact that some people just have difficulty with the letters on the keyboard. This finger want to hit a certain lettered key first, putting the correct letters out of place. I know...I know, you SHOULD proof read, but come on... don't crucify. My dad (at the age of 77) is lucky if he remembers how to spell my first name. It doesn't make him an idiot, just an old guy who has better things to think about, I suppose. I would much rather read misspelled words of someone who can teach me something, than the perfectly spelled manuscript of a bunch of bull sh* t.