As an adjective, no. → un soldat français, une danse africaine, des touristes chinois As a noun, meaning "a person from the country X", yes. → un Français, une Africaine, les Chinois Je suis français/Français. These are BOTH correct because you can place either the adjective or the noun. Languages are not capitalized. → le français, l'espagnol, le coréen...

I studied French in school for a few years, and we were taught to not capitalize them. However, even though my teacher had lived in France for a while, he was not a native speaker, so I am also keen to see the answer to your question.

A quick look on the internet seems to confirm nationtionalities (adjectives) are not, but countries (which are nouns) are, so: I am american : I speak english ( je parle l'anglais ) : I am from America. He lives in France.