认错人的英文：
mistaken identity

参考例句：

They mistake their man if they think they can frighten him.
如果他们认为可以把他吓倒，那是认错人了。

They mistake the man if they think they can frighten him.
如果他们认为可以把他吓倒，那就认错人了。

mistaken是什么意思：
adj. 错误的；弄错的
v. mistake的过去分词；弄错

You must have mistaken my intentions.
你一定是误会了我的意图了。

If you think that, you are gravely mistaken.
你若是那样想，就大错特错了

Such programs are often mistaken for corporate paternalism.
这种做法常常被误解为公司的温情主义。

It is doubtless that he has mistaken my intention.
他无疑误解了我的意思。

You must have mistaken her for her sister.
你一定是把她误认为是她的姊妹了。

identity是什么意思：
n. 身份；同一性；一致；特性；个性；恒等式

Your appearance is identical to hers.
你的相貌和她的一模一样。

They're wearing identical clothes.
他们穿着完全相同的衣服。

The police have no clue to his identity.
警察没有可以确定他的身份的任何线索。

We reach an identity of views.
我们取得完全一致的看法。

These two designs are almost identical.
这两种式样几乎完全相同。