1. "I'm itching my (insert body part here)." You are not. You are SCRATCHING an ITCH on said body part.
2. "I shouldn't of done that." No, you shouldn't HAVE.
3. "You're so clutch!" What the HELL does this even mean???
4. "They're so bipolar!" This one REALLY gets me, and it's not hard to figure out why. Someone's mood rapidly changing from high to low and vice versa is NOT the definition of bipolar disorder. Bipolar disorder means you suffer from manic episodes, which is usually characterized by extremely rapid thoughts. You're trying to say that said person suffers severe mood swings. GET IT RIGHT.
5. "I didn't sleep last night, I'm such an insomniac." Unless you have a diagnosis, quit throwing that word around. I guarantee you have NO idea what true insomnia feels like (coming from someone with a diagnosis, writing a blog entry at midnight).
6. "Irregardless," "All of the sudden," and ""I seen (something/someone)."" These are not real words or correct English. Remove them from your vocabulary.
7. "I'm feeling some type of way." And what way IS that, exactly?
8. "God is good," or "It's God's will." Ok, I KNOW I will catch flack for this one, and that's ok. This just gives me impression that you (or whomever) thinks God is sitting up on the clouds, twirling his beard while sipping a caramel mochiatto frappa-something, deciding who gets their prayers answered and who doesn't like a freaking lottery. And for me, that's not how God works, that's not what God is. So I internally die a little inside every time someone says these to me, even though I would never tell them so. I would never want to insult someone else's faith, this one just personally drives me bananas.