It's easy to make a mistake.

犯错误很容易。

《牛津词典》

Whoops, that was a mistake.

哎呀，出了个小错误。

《柯林斯英汉双解大词典》

There was a mistake over his booking.

他的预订中有个错误。

《柯林斯英汉双解大词典》

When a friend is troubled by a mistake he has made, you might tell him to forget about it.

VOA: special.2009.05.10

The passage is also famous because in it Milton does something that he almost never does. Milton has made a mistake.

这篇文章有名也是因为弥尔顿做了一些,他几乎从未做过的事，弥尔顿犯了一个错误。

耶鲁公开课 - 弥尔顿课程节选

I must have made a mistake on my project.

我肯定在项目里出什么差错了。

Must 课堂 - SpeakingMax英语口语达人

Miles Beale, the group's chief executive, is clear he thinks the government is making a mistake.

BBC: The battle over alcohol pricing

"Even many of Obama's supporters believed that the prize was a mistake, " he says.

BBC: Nobel secretary regrets Obama peace prize

But it would be a mistake to conclude that marriage, then, is the answer.

NPR: Women Of Color Lag Behind In Wealth