Czuch Chuckers: I fully understood what you said. I gave that example just because English was the only word I could think of that is both the name of a language and a nationality, beside French. That's why I asked that question.

Maybe it would have been better if I had given 'I'm a French teacher.' as an example.

But when you say you never have the stress on teacher, do you mean that when you want to say you're a teacher from Italy, you still put the stress on Italian in the sentence below?

I'm an Italian teacher.

Harley: Thank you very much for your replies. Sometimes, some questions cannot be answered without the help of native speakers.