How to Use Nauseated and Nauseous Correctly

Both "nauseated" and "nauseous" derive from "nausea," the feeling of stomach discomfort that might lead to vomiting. You use "nauseated" as a past tense verb: "I am nauseated." You use "nauseous" as an adjective meaning causing nausea: "The smell of rotten meat is nauseous." In other words "nauseous" refers to the cause of nausea, while being "nauseated" is to suffer from it.
1 "Nauseous" Examples
"Nauseous" as an adjective describes the source of what makes you sick: "The nauseous feeling arose from the nauseous smell." Reference.com notes that it can also follow a verb of appearance, change or state of being: "She looks nauseous" or "He became nauseous." As an adjective, it can modify a noun that causes nausea: "We climbed to nauseous heights."
Vocabulary Builder
2 "Nauseated" Examples
"Nauseated" is a verb that you can use with an object -- "His appearance nauseated me" -- or without one -- "I am nauseated." It's important to remember that "nauseated" is still a verb, even with a helping verb. "She feels nauseated" is a verb phrase.