I was born in Mainland China, and I feel comfortable using the term “American” to describe myself after I obtained US Citizenship. However if I were to become a citizen of the UK, or Germany, or France, I would not feel comfortable using the term British, German, or French to describe myself. Because those words are not just nationalities, but also ethnicities. Whereas there is no “American” ethnicity, so that’s why I don’t feel weird using the term. Same with “Canadian”, if I were to become a citizen of Canada.

So for people to naturalizes in countries whose demonym is also an ethnicity, do they calle themselves “British”, “German”, French", etc…? Or just “UK Citizen”, “German Citizen”, “French Citizen”?