You cannot be too careful.

　　你要特别小心。

　　此句不能按字面译作：“你不能过分小心。”因为cannot...too...是个固定结构，其义为“无论如何…也不过分”。如用英语阐述，上句相当于：You should be as careful as possible. 我们在学习英语的时候，遇到这类实际意义与其字面意义大相径庭的句子，必须小心区别，正确地理解其涵义。下面请看几个类例：

　　We cannot recommend this book too strongly.

　　这本书很好，无论我们如何推荐也不过分。

　　You can't be too careful in dong this experiment.

　　在做这个实验时，你们愈仔细愈好。

　　One cannot be too careful in matters like that.

　　人们在处理这种事情时必须非常慎重。.

　　要注意的是，cannot...too...有几个变体结构，我们可以用impossible、difficult等字去代替cannot;以enough、difficulty、sufficiently、exaggerate、to over等字去替代too。

　　下面的一些句子就是“cannot...too...”结构的变体：

　　I couldn't get home fast enough.

　　我恨不得马上回到家里。

　　You cannot take sufficient care.

　　你要特别小心。

　　The importance of this session cannot be exaggerated.

　　这次大会极为重要。

　　No man can have too many friends.

　　朋友愈多愈好。

　　L. G. Alexander编著的《New Concept English》第二册其中一课《Do You Call That a Hat?》中有这么一段风趣的夫妻对话，丈夫和妻子都用了这个句型的变体：

　　"I find it beautiful," I said. "A man can never have too many ties."

　　"And a woman can't have too many hats," she answered.

　　“这条领带很漂亮，”我说道。“男人的领带愈多愈好。”

　　“女人的帽子也是愈多愈好啊。” 她答道。

　　现在请读者将下面两个句子译成汉语：

　　We cannot too strongly inculcate (or It would be impossible to over-estimate) the importance of more teacher training to deal with student problems and prevent teenage suicides in Hong Kong.

　　The importance of the campaign against dogs in public housing estates in Hong Kong cannot be exaggerated.

　　(来源：24en.com)