翻译由多层小句组成的汉语长句，一种行之有效的方法是“切”。它常常能够化繁为简，达到表达清晰，流畅的效果。如上面引用的句子，经过老师的启发，大部分同学都把它分成了三个部分。如此切分之后，再进行翻译就不难了，如：

I have come across a great many young friends, bright and diligent, excelling in studies as they are. However they are so weak in Chinese that they can not even write a smooth letter. When I asked them why, they said they were not interested in Chinese.

1. 切分的主要依据
切分的主要依据是句了的逻辑关系。由于汉语的断句是句随意止，流水句有时铺排得很开，再加上长句缺乏形式标记，所以在切分吋，首先是理解意义，理淸各层意义之间的逻辑关系。下面的例句选自《武汉晚报》（2006年4月28日）何娅娛评专栏里的一篇名为《超女无辜》的短文：

这让我想起去年流传在网上的ー个帖子，说专家称“自行车是比汽车更大的污染”，原因居然是“因为自行车太多，影响了城市的道路交通，机动车运行缓慢，尾气排放量增加，城市空气污染加剧”。
以下列出几段较为典型的学生译文：
译文a
The above reminds me of a note that was popular on the Internet last year. Some experts said，"Bicycle is a more terrible pollution than car, because if the overwhelming bicycles block the traffic, the cars will move slowly, then the emission of exhausts will be increased. Therefore the pollution will go worse."
译文b
This reminds me of a passage circulated widely on the Internet, in which quoted some experts' opinion that bicycles are more harmful to environment than cars just because bicycles cause a lot of traffic jams and due to this, automobiles move slower and then vent more gases into the air. So the air conditions in the cities get worse.
译文c
This reminds me of a post floating about on Internet last year, which claimed that bicycles were a bigger pollution than vehicles by experts and the reason was that“there are too many bicycles which affect the city transportation and reduce the speed of vehicles; hence the amount of emission increases and the air pollution in cities deteriorates”.
分析：分句不明晰，造成语意表达不淸，结论与原因混淆，语义重心模糊甚至转移。原因可能有以下两点。
1) 对汉语的理解没有到位。原文虽三层意思，分别从背景一一结论——原因一层ー层展开，但是以上译文都混淆或打乱了原文的层次。由此可见，理解是翻译的基础，对汉语原文的理解同样如此。