How do you say 彼を嫉んで、社長のコネだなんて噂を広める前に、なぜ彼がそんなに若くして所長になったのか、本当の理由を知りなさい。実際、彼は自分ではあまり才能がないと思っていたので、人の倍、働きまた勉強したのだ。 in English?

You must know the real reason why he became the manager so young before you envy him and spread rumors, saying that he has a kind of connection with the president. In fact, he worked and studied twice as much as the others as he thought he was not so talented.