YOU SAID:

He is really good at what he does

INTO JAPANESE

彼は自分のやって本当に上手だ

BACK INTO ENGLISH

He is really good at what he does.

INTO JAPANESE

彼は自分のやりが本当に上手だ。

BACK INTO ENGLISH

He is really good at his own way.

INTO JAPANESE

彼は自分のやり方が本当に上手だ。

BACK INTO ENGLISH

He's really good at his way.

INTO JAPANESE

彼は自分のやり方が本当に上手だ。

BACK INTO ENGLISH

He's really good at his way.