A word that we commonly use that is one of the hardest words out of the dictionary to spell correctly. Most people just use spell check to fix it, but without it spelling this word right is frustrating. A straight pain in the ass.
BEFORE: Therefore I gaurentee that the facts support my thesis.
F**K I never spell this word right, thank God for spell check.
After: Therefore I guarantee that the facts support my thesis.
Ah, there we go maybe I'll spell it right next time.