NOTE: Any spell-check program ought to catch most of these for you. However, the wisest course is to master them yourself.
For fun, I did a search for the incorrect version of nine of the ten. I didn’t bother with Number 7 because both its and it’s are valid spellings. The number of hits for the misspellings is shown in parentheses. Some refer to intentional misspellings on English sites like this one, but not all.
1. argument
(“arguement” 730,000)
The verb is argue, but the noun is argument.
2. calendar
(“calender” 29,600,000)
The register on which you schedule your appointments is spelled calendar. Yes, there is a specialized term spelled calender that refers to paper production, but I doubt that it accounts for millions of uses.
3. cemetery
(“cemetary”185,000,000)
There are three e’s in cemetery. Nary an a in sight.
4. definite
(“definate” 539,000)
Think, finite, infinite, infinity. Look at all those i’s. No a’s anywhere in definite.
5. finally
(“finaly” 1,450,000)
The adjective is final. The adverb is finally. Double that l in finally.
6. forty
(“fourty” 783,000)
One less than five is spelled four. One more than thirty-nine is spelled forty.
7. its (possessive adjective)
The problem with this habitual misspelling is that both its and it’s are English spellings. It’s is a contraction of the words “It is.” Its is a possessive adjective, like his. The best advice is to spell out “it is” when that is your meaning. You cannot rely on grammar/spell checkers to catch this one. Indeed, Word often advises me to write “it’s” when the context calls for its.
8. separate
(“seperate” 31,700,000)
Take the word by syllables: sep-a-rate. Yes, we pronounce it [sep-uh-ret], but we spell it sep-a-rate. Look for “a rat” in sep.a.rat.e.
9. tragedy
(“tradgedy” 212,000)
The g in tragedy is soft. The e makes the g soft. No extra d, please.
10. truly
(“truely” 62,600,000)
The adjective is true. The adverb is truly.
I SO relate to this post. I cannot spell “calendar” off the top of my head to save my life.
And I think one of the problems about “it’s” and “its” is that while the other possessive pronouns–his hers theirs ours–do not have apostrophes, other possessive nouns–Andy’s, mom’s, the diner’s, California’s–do, so no matter what rule you try to remember as your key, there is likely to be a counter argument that pops into your head as you type!
How about colledge. I see that all the time. Maybe that’s a school that is precariously close to financial exigency. THAT would explain the commonness of it!
There is a pronounced tendency (ha!) for some, particularly Americans as Brits tend not to stress much at all, and even more so for somewhat educated Americans to “overpronounce” certain. Hence we get jur-ORs and legislat-ORs and bursARs and vend-ORs, probably due to misguided notions of precision and in some cases self-conscious needs to display spelling awareness (remember Fowler on often?).
People don’t, however, say calend-Ar, which leaves a perfect amount of room to assume the spelling must be –ER. This would also explain grammer, ceder, piller, caterpillar, etc. Likewise maybe separate would not be as counter-intuitive if it was known AR can be an UR sound, too. If people were comfortable with knowing it’s okay to say jur-ur or legislat-ur, or burs-ur, maybe they actually be MORE attuned to spelling…nah, pro’ly not.
I don’t have a problem with every one of these words, but I definitely catch myself spelling a lot of them wrong while writing, especially when I’m in somewhat of a hurry. For some, it actually took me a long time to train myself to spell them correctly. It made me a feel a little dopey to be honest, but knowing that it’s pretty common makes me feel a little better.