1) This is where the mistakes come in.

这是出错的地方。
2) Unfortunately, this is not quite correct.

这是错的。
3) This is utterly wrong.

这是大错特错的。
4) It is a mistake pure and simple.

这是纯粹的错误。
5) Evidently you are in the wrong.

这分明是你的错。
6) I maintained that it was wrong.

我认定这是错的。
参考词条