Should there be an article 'a' with a race?
I'm a Chinese or I'm Chinese.
We normally talk of our own and other's nationality, not their race. About the only time I ever refer to myself as 'Caucasian', is when, in talking about people's reactions to seeing my colleagues and me for the first time when we worked in China, I say "We were the only Caucasians within five hundred miles of the town".
I normally say, depending on the situation, "I am English" or "I am British". I never say, "I'm an Englishman" or "I'm a Briton". Of a Chinese or Japanese colleague, I would only ever say say "S/he is Chinese/Japanese", with no article.
We have to fill in ethnicity on many forms too- there are over 200 languages spoken in London and we're a diverse society. We don't ask people directly about this, but we could ask about nationality. And we generally don't use the indefinite article.
There are many cultural differences- I find it weird to be asked how much money I make, a question I have never asked my brothers. That's what makes the world so interesting.
Who is asking you that? Unless it's on a job interview or with the tax man, it's a "none of your business" question for sure.
Yes, I agree. I have been asked many times about my race because many think that I am Chinese, which I am not, like, 'Are you Chinese?' Or 'Is any of you parent Chinese?'
But then again, to learn a language is to learn its culture too.