日本語、難しいね。
Japanese is difficult, isn't it?
日本語が少し話せるからね。
Because I can speak a little Japanese, you know.
日本語話せますか?
Can you speak Japanese?
— 親切なクムジャさん (2005)
彼は合衆国で育ったが、母語は日本語です。
He grew up in the United States, but his native language is Japanese.
私は、母語も母国語も日本語だよ。
Japanese is both my mother tongue and my native language.
日本語版があったらいいな。
It would be nice if there were a Japanese version.