AHHHHHHH!!!
It's called spell check! If there is a red line under the word that you just typed...IT'S SPELLED INCORRECTLY!!!
I realize that not everyone is capable of using the small percentage of the brain that the rest of the population uses but this is just too freakin easy.
General rules for spelling....
http://www.uwm.edu/Dept/English/wcenter/WCO4/handouts/setii/SETII36P.html
Oh...and sometimes...even if the word is spelled correctly..you're using it incorrectly!!!
eg:
you're, your
they're, there, their
affect, effect
board, bored
scarred, scared
lead, led
aloud, allowed
morning, mourning
Get a freakin clue!
BTW..I totally spelled checked this field. I know that "freakin" is misspelled. It's deliberate!