Maybe the way he was raised by his parents wasn't very good.
Maybe his parents did a poor job of bringing him up.
この場合、次のような言い方ができますよ。
ーMaybe the way he was raised by his parents wasn't very good.
「彼の両親の育て方が悪かったんじゃない」
the way he was raised by his parents で「彼の両親の育て方」
ーMaybe his parents did a poor job of bringing him up.
「彼の両親は彼を育てるのに失敗したんじゃない」
to do a poor job of bringing him up で「彼を育てるのに失敗する」
ご参考まで！
カナダ 
