自行其是

I couldn't see the point of letting him have it his own way.

我不明白让他其是有什么道理。

You’re a maverick and you’ll try anything.

你是个爱其是的人, 样样事情都一下。

The committee was doing well until the chairman's independent action gummed up the work.

委员会的工作原进展得很顺利, 后主其是, 把事情弄糟了。