" I am a native Japanese." この人は科学的根拠のないことを言っています。生まれたときあなたはただの人間でした。日本人に後でなるかどうかは、育つ環境弐よるものです。 そして、"we Japanese"という言い方はもはや世界の人に嫌われます。も、江戸時代ではないぞ！ Why you cannot pronounce Mandarin is simply because you do not learn the alphabet before you start learning kana and kanji. Your pronunciation is ruined for ever by the 40,000 katakana English words used daily by the Japanese people. If you did not learn a second language before th age of 5, give up--it's TOO LATE. To everyone writing about language learning, if you are not a trained linguist, you are not qualified to write anythiing!