如：The boy, whose father is an engineer, studies very hard.

这个男孩，他的爸爸是一位工程师，学习很努力

Above the trees are the mountains, whose magnificence the river faithfully reflects on the surface.

在树林的高处是山，其壮丽的景色完全映照在河面上。

The play，whose style is rigidly formal，is typical of the period.

这剧本是那个时期的典型作品，风格拘谨刻板。

关系代词which在非限制性定语从句，中所指代和修饰的可以是主句中的名词、形容词、短语、其他从句或整个主句，在从句中作主语、动词宾语、介词宾语或表语。

① which指代主句中的名词，被指代的名词包括表示物、婴儿或动物的名词、表示单数意义的集体名词以及表示职业、品格等的名词。

如：These apple trees，which I planted three years ago，have not born any fruit.

这些苹果树是我三年前栽的，还没有结过果实。

She is an artist，which I am not.

她是一位艺术家，而我不是。

Water，which is a clear liquid，has many uses.

水是一种清澈的液体，有许多用途。

The two policemen were completely trusted，which in fact they were.

那两个警察完全受到信任，事实上也确实如此。

② which指代主句中的形容词。

如：She was very patient towards the children，which her husband seldom was.

她对孩子们很耐心，她丈夫却很少这样。

She is always careless，which we should not be.

她总是马虎大意，我们可不应该这样。

③ which指代主句中的某个从句。

如：He said that he had never seen her before，which was not true.

他说以前从没见过她，这不是真的。

④ which指代整个主句。

如：In the presence of so many people he was little tense, which was understandable.

在那么多人面前他有点紧张，这是可以理解的。

He may have acute appendicitis，in which case he will have to be operated on.

他可能得了急性盲肠炎，如果是这样，他就得动手术。

When deeply absorbed in work，which he often was，he would forget all about eating and sleeping.

他经常聚精会神地工作，这时他会废寝忘食。

关系副词when在非限制性定语从句中作时间状语，指代主句中表示时间的词语。

如：He will put off the picnic until May 1st, when he will be free.

他将把郊游推迟到5月1号，那时他将有空。

副词where在非限制性定语从句中作地点状语，指代主句中表示地点的词语。

如：They went to London，where they lived for six months.

他们去了伦敦，在那儿呆了六个月的时间。

as引出非限定性定语从句时，代替整个主句，对其进行说明但通常用于像as we all know, as it is known, as is known to all, as it is, as is said above, as always mentioned above, as is usual, as is often the case, as is reported in the newspaper等句式中。as在非限定性定语从句中作主语、宾语，且引出的从句位置比较灵活，可位于句首或句末，也可置于主句中间。通常均由逗号将其与主句隔开。as有“正如……， 就像……”之意。

如：As is known to the United States, Mark Twain is a great American writer.

美国人都知道，马克·吐温是一位伟大的美国作家。（as在从句中作主语）

He forgot to bring his pen with him, as was often the case.

他忘了带笔，这是常事。（as在从句中作主语）

He is absorbed in work, as he often was.

他正在全神贯注地工作，他过去经常这样。（as在从句中作表语）

As we all know, the earth is round.

众所周知，地球是圆的。（as在从句中作宾语）

The two brothers were satisfied with this decision，as was agreed beforehand.

两兄弟对此决定都满意，这项决定在事前都已得到他们的同意。(as在从句中作主语)

Taiwan is，as you know，an inseparable part of China.

你知道，台湾是中国不可分割的一部分。(as在从句中作宾语)

as it is known to all (that...) (as 做状语从句连词，是状语从句, 可以加that)

与 as is known to all (as做主语，是定语从句)

与 it is known to all that... (主语从句，it是形式主语)

即：As is widely known, the moon is closer to us than the sun.(定从)

= That the moon is closer to us than the sun is widely known.(主从)

= It is widely known that the moon is closer to us than the sun.(主从)

As it is known to everyone, I thought you knew about it too.(状从)

关系代词which有时并不代表主句中某一确定的词，而是概括整个主句的意思。介词的选择取决于它与先行词的搭配或与从句中谓语动词的搭配。

They were short of sticks to make frames for the climbing vines，without which the yield would be halved.

他们缺搭葡萄架的杆儿，没有它们产量会减少一半。

They thanked Tom，without whose support they would not have succeeded.

他们很感激Tom，没有他的支持他们是不会成功的。

“介词+关系代词”引导非限制性定语从句：在介词后引导非限制性定语从句。

“名词/代词+of+which / whom”

It now has 20，000 hectares of land，more than two-thirds of which are under cultivation.

现在它拥有两万公顷土地，其中三分之二之多已经耕种。

Light is the fastest thing in the world, the speed of which is 300000 kilometer per second.

光是世界上最快的东西，它的速度是每秒30万千米。

There are 30 chairs in the small hall, most of which are new.

大厅里有三十把椅子，绝大部分是新的。

The textile mill has over 8，000 workers and staffs，eighty per cent of whom are women.

这家纺织厂有8千多职工，女职工占百分之八十。

即“引导定语从句的关系词”

①引导非限定性定语从句的关系代词：as,which,who,whom

②引导非限定性定语从句的关系副词主要有：when,where。

注意

不能用that作为关系代词的两种情况：

①非限定性定语从句

②介词+关系代词

1、as引导的定语从句可以放在句首、句中和句尾，which引导的定语从句可置于句中或句尾。

2、关系代词as在限定性定语从句中后跟“be动词+过去分词”的被动语态时，be动词可省略。

3、 as有时也可用作关系代词 。若as在从句中作主语，其引导的句子可以放在句首或句中。但which引导的非限制性定语从句只能放句中。

4、as有正如…一样、按照、正像、因为的意思，所以常用于肯定句，而which则用于肯定，否定都可以。

5、在固定结构中使用as 例如：the same … as 、as … as。

例句：

1 Dorothy was always speaking highly of her role in the play, which , of course, made the others unhappy.（从句部分的意思为：这当然使别人不高兴；而不能译为正如使别人不高兴。故用which。）

2 Chongqing is not the same city as we have seen in other places.

重庆和我们在其它地方看过的城市不一样。

1. 引导限制性定语从句时，关系代词which可以与that互换；但引导非限制性定语从句时，只能用which。

例1.She heard a terrible noise, ______ frightened her.

A. that B. which C. what D. who

例2.She heard a terrible noise ______ frightened her.

A. that B. / C. what D. who

解析： 例1意为：“她听到一个可怕的声音，这使她感到恐惧。”that不能用于引导非限制性定语从句，故选B。例2意为：“她听到了一个使她恐惧的可怕声音。”引导修饰noise的限制性定语从句可以用which或that来引导,故选A。

2. 先行词为reason时，限制性定语可以用why或for which来引导；非限制性定语从句则只能用for which来引导。

例3.I had told them the reason, ______ I didn’t attend the meeting.

A. for which B. at which C. for whom D. why

例4I had told them the reason ______ I didn’t attend the meeting.

A. when B. which C. why D. for that

解析： 例3意为：“我早已把理由告诉了他们，于是我没有出席会议。”先行词为reason时，非限制性定语从句应用for which引导，故选A。例4意为：“我已经把没有出席会议的原因告诉了他们。”the reason why...是常见搭配，答案为C。

3. 引导限制性定语从句的关系代词在从句中担任宾语且前面没有介词时可以被省略；但引导非限制性定语从句的关系代词无论作主语还是作宾语还是作定语，无论前面是否有介词都不能被省略。

例5.He was eager to go to the hospital to see his stepmother,______ he loved and respected as his own mother.

A. as B. which C. / D. whom

解析： 本句意为：“他急于去医院看望他的继母，他像对待亲生母亲一样孝敬她。”关系代词whom引导非限制性定语从句并作宾语，不能被省略，故选D。

4．引导限制性定语从句时并作从句宾语的关系代词whom前没有介词时可以用who来代替；但在非限制性定语从句中，whom无论前面是否有介词都不能用who替换。

例6. Do you know Tom, _____ we talked about?

A. which B. that C. whom D. who

例7.The American journalist ______ the announcer mentioned in the news broadcast is said to have been killed by the gangsters. Which of the following is wrong?

A. who B. whom C. whose D. /

解析： 例6意为：“你认识汤姆吗? 我们谈到过他。”应选C。例7意为：“播音员在新闻广播中提到的那位美国记者据说已遭歹徒杀害。下列哪一项是错误的？”关系代词作mentioned的宾语且指人时，可用who/whom/that，在限制性定语从句中可省略，故C是错的。

5．当非限制性定语从句修饰整个主句时，其关系代词可以用as 和which，但位于句首不能用which，只能用as。此时非限制性定语从句可置于主句之前、之后或之中。

例8______ I expected, he didn’t believe me.

A. Which B. As C. That D. When

解析： 本句意为：“正如我所预料的那样，他不相信我的话。”非限制性定语从句修饰整个主句，应用as引导，故答案为B。

例9.Mary was late for school,______ often happened.

A. as B. for which C. that D. why

解析： 本句意为：“玛丽上学迟到了，这是常有的事。”根据句意，关系代词as引导的非限制性定语从句修饰前面的主句，其位置非常灵活，故答案为A。

6. 由“介词+关系代词”引导非限制性定语从句，关系代词指代整个主句时，不能用as，只能用which，因为有介词关系。

例10.He bought the car for more than $20,000,______ his father was angry.

A. about that B. with as C. when D. with which

解析： 本句意为：“他花两万多美元买了这辆车，他父亲对此很生气。”which位于介词with的后面，指代前面的主句，故答案为D。

1. which引导的非限定性定语从句是用来说明前面整个句子的情况或主句的某一部分。

2. as有时也可用作关系代词 。as引导非限制性定语从句，若as在从句中作主语，其引导的句子可以放在句首，也可以放在句中。但which引导的非限制性定语从句只能放句中。

例句：

As is reported in the newspaper ，some artistic treasures（艺术珍品） will be on show at the exhibition （展览品）on the weekend.

3. 在非限定性定语从句中，关系词不能用that,和those。

1.限定性定语从句：从句不能省略，如果省略整个句子意思不完整。

非限定性定语从句：从句可以省略，如果省略整个句子意思仍然完整。

2.限定性定语从句：先行词可以用that引导。

非限定性定语从句：先行词不可以用that引导。

3.限定性定语从句：引导词有时可以省略。

非限定性定语从句：引导词不可以省略。

4.限定性定语从句：主句与从句不可以用逗号隔开。

非限定性定语从句：主句与从句可以用逗号隔开。

5.限定性定语从句：从句只修饰先行词。

非限定性定语从句：从句既可以修饰先行词，也可以修饰整个句子或句子的一部分。

6.限定性定语从句：不能修饰一个事件。

非限定性定语从句：可以修饰一个事件。

限定性定语从句与主句的关系很紧凑，对其先行词起限定、修饰的作用。如果将其去掉，会影响句子意思的完整性；有时甚至于引起费解、误解。例如：

1.Rainforests are being cleared for valuable timber and other resources to speed up the economic growth of the nations in which they are located .

为了加速他们各自所在国家的经济发展，热带雨林作为有价值的原木和其他资源正为人们所砍伐。

2.Ocean currents affect the climates of the lands near which they flow.

洋流影响其流经的附近地区的气候。

3.They explained the reason to us why they had hated us before.

他们向我们解释为什么他们不喜欢我们的原因。

Earlier , the Babylonians had attempted to map the world , but they presented it in the form of a flattened disc rather than a sphere , which was the form adopted by Ptolemy .

更早之前，巴比伦人曾试图绘制世界地图，但是他们把它绘制成平盘状而不是托勒密所采用的球体状。

（此句中，非限定性定语从句是对先行词a sphere进行补充、说明。）

The combination of satellites, which transmit information , computers , which store information , and television , which displays information , will change every home into an education and entertainment center .

卫星能传输信息，计算机能储存信息，电视能显示信息，把这些手段结合起来可以使每个家庭都成为教育娱乐的中心。

（此句中，三个非限定性定语从句分别对三个先行词：satellites ，computers和television进行补充、说明。如果去掉这三个非限定性定语从句，那么句子可简化为：The combination of satellites , computers and television will change every home into an education and entertainment center .）

The sun heats the earth , which makes it possible for plants to grow .

太阳给予大地热，这就使植物的生长成为可能。

The old man has a son , who is in the army .

那位老人有一个儿子，他在部队工作。