Years ago Sheila and I worked in a biology lab in France. There was a French graduate student, a clean-cut young man and a clothes-horse, who spoke English well but imperfectly.
One feature of clean-cut young men is that they’re frequently shocked by things.
This young man missed one of the fine points of English. Whenever he was shocked, he would declare, loudly and indignantly, “I’m shocking!”
We never corrected him because it was so funny. He was the farthest thing from shocking, a most un-shocking young man. So to hear him stand up and declare, with Gallic indignation and a French accent, that he was shocking—well, it made us laugh like the crazy hamburger-eaters we were.
I’ve found that even native English speakers make a similar mistake with the word nauseous.
Whenever someone says or writes that they’re nauseous, I laugh, because it’s the same mistake my French friend made.
Something that’s nauseous is something that causes nausea.
If you’ve been affected by something that’s nauseous, then you have been nauseated.
Get it? Saying “I’m nauseous” is like saying “I’m shocking!”