0553名無しさん@英語勉強中 (ニククエ a1cc-GHdW)
2018/04/29(日) 15:24:55.10ID:j33iRmI80NIKUit's a bit rough, but GRAMATICALLY correct. Better to
say: I am an American speaker, not a Japanese one.
Correct but confusing, "not a Japanese" could mean you
are not a Japanese person or dont speak Japanese.