我是五年级的老人，以前国中时，很流行考一种文法题
He is ___________.
(A) Chinese (B) a Chinese
杨荣一和其他参考书公布的答案都是B.
考上了建中，高二的英文老师据说是师大英语系第一名毕业，
他上课时主动提起这题，说A也对。
最近听到外国人说A才对，B很罕见，不能算是对的选项。
Wiktionary usage note:
As with all nouns formed from -ese, the countable singular form ("I am a
Chinese") is uncommon and often taken as incorrect, although it is rather
frequent in East Asia as a translation for the demonyms written 中国人 in
Chinese characters or Japanese kanji.
可参阅http://goo.gl/V8DJ8d
https://www.englishforums.com/English/IAmAChinese/bkgcrr/post.htm