I was so angry, I whooped?

Whoop: "a loud cry or shout, as of excitement or joy" (from dictionary.com)

"I'm gonna whoop your butt!" - angry parent to child who just did something bad.

What's wrong with this picture? How do you shout someone's butt? This misspelling has become so prevalent, it's listed on urbandictionary.com with the incorrect definition. Clearly this originally came from "whip" which some people pronounce "whup" which sounds like "whoop." But why not just write "whup"? Do they think that looks stupid? Let me let you in on something: using "whoop" to mean whip/beat looks a lot stupider. At least, if you write "whup" it's obvious that you're using slang spelling on purpose.

Loose vs Lose

One of the things that bothers me the most is when someone uses the word "loose" when they mean "lose." The two words have similar meanings, but they're not the same. "To loose" means "to free from bonds or restraint. To release, as from constraint, obligation, or penalty." (from Dictionary.com) "To lose" means "to fail to keep, preserve, or maintain. To suffer the deprivation of." (from Dictionary.com)

Obviously, the reason so many people have such a problem with these words is that 'o' is not often pronounced 'oo.' However, I have never seen someone write "moove" when they meant to write "move." This is probably because "moove" is not a word, while "loose" is.

This mistake is probably one of the most common grammatical/spelling errors on the Internet, and it seems to be getting more and more prevalent. I think when we see errors enough, they start to look right to us, and then we have the tendency to make the same mistakes.