I've done my best.

我已经尽力了。

youdao

Tell my mom I've done my best!

告诉妈妈我已经尽力！

youdao

I've done my best with her, but I can't help it.

我已尽了最大的努力去劝说她，但无济于事。

youdao

Now, I've done my best to peg the readings to where I will be on that week's lecture, but I don't lecture with lecture notes, for the most part.

现在我已经尽力,为那周要做的讲座,收集很多阅读的材料，大部分时候我不按照讲稿来讲课。

耶鲁公开课 - 死亡课程节选

"I cannot say I've been the best, but I can say I've done my best for 13 years" as a musician, he said.

NPR: Korean Pop Sensation Cracks Jokes At Harvard

I've done my best to be your friend, but I also let you down and I let my family down and I let this country down.

CNN: Transcript: Clinton's remarks at Orlando fund-raiser

"It's been the best thing I've ever done and it's given me complete happiness and joy in my social life, " he said.

BBC: Famous choir's blue plaque honour