YOU SAID:
hi are you my dad he left 15 years ago
INTO JAPANESE
こんにちは、15年前に彼が去った父です。
BACK INTO ENGLISH
Hello, I'm the father he left 15 years ago.
INTO JAPANESE
こんにちは、私は彼が15年前に去った父です。
BACK INTO ENGLISH
Hello, I am a father he left 15 years ago.
INTO JAPANESE
こんにちは、私は彼が15年前に去った父です。
BACK INTO ENGLISH
Hello, I am a father he left 15 years ago.
That didn't even make that much sense in English.