Halp What words can you never spell correctly?

fly

omg
Oct 1, 2004
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Marklar
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mattressfish
Here are a couple of mine:

definitely (I usually spell this SO wrong that Chrome's spell checker has no idea what word I'm trying to type)
caffiene

I have no idea what my mental block with them are. Now, so that I don't look like an idiot alone, what are yours?
 
Because of this retarded thing us humans possess called muscle memory and one of my internet usernames, I always screw up spelling "customer", as "cutsomer".
 
the canadian in me adds a "u" to a bunch of words, and spellcheck always bitches about it, but that's how we roll.

words like neighbour, favour, etc.