例句：
I found a mistake in that sentence.
我发现那个句子有一个错误。
You've made several grammatical mistakes in the composition.
你的作文中犯了几处语法错误。
They made the big mistake of thinking they could seize its border with a relatively small force.
他们大错特错，居然认为以较少的兵力就能够夺取其边境地区。