Anyone can look words up in a
dictionary, and of course
Webster 1913 is a great tool, but there is a new option that lets one use logic while figuring out how to spell words.
This works best where one has the options narrowed down pretty solidly to a few
candidates.
Go to your favorite
search engine (I prefer
google) and enter each candidate into the
search box on successive searches. Don't bother looking at the links returned, just note how many items there are for each candidate. One of them, the
correct one, will have a number of
results at least an
order of magnitude greater than the others. That's the correct spelling.
For example, a search today,
February 17, 2001, using Google returned:
VARIATION RESULTS
corolary 239
corrolary 1,590
corollary 206,000
corrollary 984
Clearly corollary is the correct spelling.
This is a very quick method, especially given a fast connection, and one doesn't get bogged down reading definitions. There is the temptation to scan the contents of websites containing the worst misspellings to deal with though...
July 2007:
To make things even easier, Google now offers suggestions when it seems one might have misspelled a word, i.e. "Did you mean _________?"
Combine this with a browser that has a text-box up by the address bar that's linked to a search engine and you truly have one stop shopping.