But it was a mistake!

但那是个错误！

He made a mistake with his timing.

他在时间上出了错。

Lingling made a mistake in grammar.

琳玲犯了一个语法错误。

The girl makes a mistake when she speaks to the King.

小女孩在和国王说话时犯了一个错误。

This is possibly a mistake.

这可能地是个错误。

He admit he made a mistake.

他承认自己犯了错误。

Mea culpa, I made a mistake.

我的错，我犯了一个错误。

Everyone can make a mistake.

每个人都会犯错。

We made a mistake in the exam.

我们在考试中犯错了。

He made a mistake in the exam.

他在考试中出错了。