If you’re one of the millions of viewers who watch BIG BANG THEORY, you’ve been treated to Sheldon Cooper’s numerous grammar lectures. One of my favorites is about nauseous versus nauseated. He says people often say they’re nauseous when they mean they’re nauseated.

I have a similar pet peeve with incredible versus incredulous. Do you use incredulous correctly?

Wrong: She felt incredulous guilt for her father’s death.

Correct: She felt incredible guilt for her father’s death.

Both are adjectives. Incredible means implausible or extraordinary. Incredulous means disbelieving or skeptical. A trick that helps me is substituting the synonym skeptical. If the synonym makes no sense, I’ve used incredulous incorrectly. (e.g. Skeptical grammar cop is nauseated)

Wrong:  That news story is simply incredulous.(You wouldn’t write That news story is simply skeptical.)

Correct: He read the news story, incredulous that anyone would believe such nonsense.

The bottom line: Use incredulous sparingly and never when you should use incredible.

Bonus: If you don’t watch BIG BANG THEORY, nauseated means you feel as if you might vomit. Nauseous means to induce nausea. Again, nauseous is seldom used and rarely used correctly. Just remember if you feel icky, you’re nauseated. If your body odor makes those around you feel icky, you’re nauseous. ;-)