Tory Spelling
The most commonly misspelled word in the English language is "supersede," according to some survey quoted in London's Daily Telegraph, which opines that perhaps the root of our most common misspellings is simply that some people are too "clever." Ummmm, if by clever you mean American…colour me impressed! [But click for evidence that, on this matter at least, those clever Brits have not "superceded" us yet.]