I am Chinese.中Chinese前用不用加a?

I am Chinese.为什么Chines前不用冠词a?都哪些国家的人,前面不用冠词?例如,他是一个英国人.她是一个美国人.等等我是中国人I'm Chinese我是美国人I am an American在这两个句子中Chinese和American显然都 I am Chinese.中Chinese前用不用加a? i am not chinese i am nativer chinese 为什么 I am Chinese中没有冠词a i am proud i am a chinese I am Chinese.Chinese的词性 I am a Chinese还是I am Chinese 是i am a chinese 还是 i am chinese I am Chinese.I am a Chinese.哪个句子正确 chines I am Chinese .nom student . I am good at Chinese. i can speak chinese,but my computer can't type chines sorry,can we chat by phone. 8,—Peter,is there anything else you want to know about China?—Yes,I am stillwondering __________ .A.how is Chinese paper cutmadeB.how was the Great Wallbuilt in ancient timesC.why the Chinese people liketo play the dragon danceD.why do the Chines I am Chinese.VS I am an American.有人说：只有I am Chinese.没有（或者说不正规）I am a Chinese.那为什么有I am an American.(我认为有)顺便问下在“I am Chinese”中,Chinese是名词还是形容词? I LOVE china,I am chinese! I am a China girl还是Chinese