However strong you are, there's always someone stronger.; For every able person there is always one still abler.

强中自有强中手， 能人背后有能人。

《新英汉大辞典》

He is, without a doubt, a very able person.

他毫无疑问是一个很能干的人。

youdao

He does not seem to be a particularly able person.

他似乎不是一个特别能干的人。

youdao

And it is not for me to set myself up as the one person able to answer it.

VOA: special.2009.04.18

In a less technical way, " it is helping the person to become the best that he is able to become."

通俗点讲，就是帮助一个人成为最好的自己“

哈佛公开课 - 幸福课课程节选

Suppose we say then that to be alive as a person is to be able to engage in P-functioning.

假设我们说作为人而活着,就是有人格功能性。

耶鲁公开课 - 死亡课程节选

If you aren't able to attend in person, you'll still be able to tune in to two full days of livestreamed coverage right here on Engadget.

ENGADGET: Announcing Engadget Expand, a live event and expo for gadget fans!

The issue is: is a person able to acknowledge their deficits and seek help.

CNN: Have an incompetent boss? You're not alone

"Why shouldn't people with disabilities get in through the same door as any able-bodied person, " he said.

BBC: Disabled protesters' front door battle