▲英语可以说 find sb out，意思是 “发现或知晓某人做了不好的事情”（to learn the unpleasant truth about someone）。如：

He had used a false name for years before they found him out. 他使用了假名多年后被查出。

He was stealing their money, but they soon found him out. 他在偷他们的钱，但他们很快几查出来了。

It was only a matter of time before someone found him out. 他的行为被人发现只是个时间问题。

He pretended to be a respectable citizen, but we found him out at last. 他装作是可敬的市民，但我们最终认清了他的真面目。

▲若说 find sb，则只是表示“找到某人”。如：

She sighed her relief when she found us. 找到我们时她松了口气。

He pledged never to come back until he found her. 他发誓找不到她就绝不回来。

I spent ages looking for her before I found her. 我花了很长时间找她才把她找到。

▲顺便补充一句，有时find sb out 可能表示“发现某人不在家”（此时的find out不是习语，其中的out作宾补）。如：

We went to his home but found him out. 我们去他家，但是发现他不在。