非限定性定语从句和限定定语从句的区别

一. 限定性定语从句,顾名思义,是对先行词从本质或特征上进行限制的一种定语从句,它所修饰的词代表一个(些)或一类特定的人或事、物.例如:

A man who doesn't learn from others can't achieve much.一个不向别人学习的人是不能有多少成就的.

A man被限定后,指一类特定的人.这类定语从句是不能去掉的,否则剩下的部分就失去意义不能成立,或者含义不清,甚至让人感到莫名其妙.非限定性定语从句则不然,它只对所修饰的词作进一步的说明,去掉之后并不影响句子的整个含义.在形式上,非限定性定语从句与主句之间通常用逗号隔开.例如:

Finally we visited to the Giant Yangtze Gorges Dam,which is the greatest key water control project in the world at present.最后我们参观了长江三峡大坝,它是目前世界上最大的水利枢纽工程.

本句若去掉从句,主句部分的含义仍然完整.历年的高考中,非限定性定语从句都是出现频率最高的考点之一.因此值得我们注意.

二、引导非限定性定语从句时,只能用which(不用that).例如:

Heat is another form of energy,which is as important as other kinds of energy.热是另一种形式的能量,与其他形式的能量一样重要.

从句表补充说明,而且关系代词which不能换成that.

三、引导非限定性定语从句的which可以指代前面的先行词,也可以指前面整个句子的含义.例如:

That Peter will marry Alice,which has not been announced yet,has spread around.彼特要娶爱丽斯这件事还没宣布,却已传得沸沸扬扬.

句子中的which指"彼特要娶爱丽斯"这整个句子的意思.

四、除which外,还可用when,where,who等关系代、副词引导非限定性定语从句.例如:

After graduation,I decided to stay in Chongqing,where I spent my childhood and four years of college life.毕业后,我决定留在重庆,在那里我曾度过了我的童年和四年大学生活.

Albert Einstein left Germany for the United States during World War II,when Jews were badly treated in Germany.第二次世界大战期间,爱因斯坦离开德国去了美国,那时犹太人在德国受到不好的对待.

五、在限定性定语从句中作宾语时,引导词可以省略,但引导非限定性定语从句的关联词不能省.试比较:

He was eager to go to the hospital to see his stepmother,whom he loved and respected as his own mother.他急于想去医院看望他的继母,他把他的继母当作亲生母亲一样热爱和尊敬.

The American journalist (whom / who) the announcer mentioned in the news broadcast is said to have been killed by the gangsters.播音员在新闻广播中提到的那位美国记者据说已经被匪徒杀害了.

两例中的关系代词都在从句中作宾语.由于第二例是限定性定语从句,可以省略关系代词;第一例中的引导词不能省略,因为它引导的是非限定性定语从句.

六、表示"正如"的含义时,通常用as引导非限定性定语从句,也可用which引导;但置于句首时,只能用as引导.

例如:

China has basically succeeded in defeating SARS,which / as we have expected.正如我们所预料的那样,中国已基本上战胜了"非典".

As is well known to everybody,Taiwan is an inseparable part of China.众所周知,台湾是中国不可分割的一部分.

但是当非限定性定语从句是否定含义时,就只能用which(而不用as)引导.例如:

He didn't win the championship,which I hadn't expected.他没获得冠军,这一点是我没预料到的.

or:

按照我的理解，最根本的区别：如果将非限制性定于从句从原句中去掉，原句依然有着明确而完整的意思；如果将限制性定语从句去掉，原句将意思不清。