However, I'm finding this doesn't work as well as expected. Most misspelled words seem to involve letters in the wrong order, or words that don't follow common rules. The above approach doesn't work for either of these issues. For example, there is no good substring for the spelling "accidant".
I'm looking for a more effective method of determining if a word is probably misspelled or not, ideally something that solves the issues of letters in incorrect order and keys near the correct letter on a keyboard accidentally being pressed (but solutions to other common causes of misspellings are fine).
This is english-only, so it doesn't need to work with other languages. Also, false positives are a much larger problem for me than false negatives, so I would prefer to err on the side of saying words are spelled correctly when in fact they are not.