I am afraid that I have made a mistake.

我担心自己犯了一个错误。

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I have made a mistake.

我已经犯了一个错误。

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I recognize that I have made a mistake.

我认识到我犯了一个错误。

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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

Nor was I misleading on the day that the president decided to go to war when I said that he had made a mistake in not building strong alliances, and that I would have preferred that he did more diplomacy.

NPR: Transcript of Presidential Debate

I'm not going to have a go at Willie Collum, I think he's a smashing referee, but he's made a mistake.

BBC: Hamilton manager Billy Reid

"I have made a mistake, " the clinically blind politician said in press conference later in the day.

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