YOU SAID:

when you try your best but you don't succeed

INTO JAPANESE

あなたが最善を尽くすが成功しないとき

BACK INTO ENGLISH

When you do your best to be unsuccessful

INTO JAPANESE

成功するために最善を行うとき

BACK INTO ENGLISH

When doing your best to succeed

INTO JAPANESE

成功するために最善を尽くしているとき

BACK INTO ENGLISH

While doing your best to succeed

INTO JAPANESE

成功するために最善を尽くしている間

BACK INTO ENGLISH

While doing his best to be successful

INTO JAPANESE

成功するために彼の最善を尽くしている間

BACK INTO ENGLISH

While doing his best to be successful