as和which引导非限制性定语从句的区别

关系代词as与which引导的非限制性定语从句，其先行词都可以是整个主句，指代主句的整个意思。但as和which具有不同的词义、句法和用法。

1. as引导的从句表示说话人的看法、态度、解释或评论

引导定语从句时，as仍具有“正如，像，由……可知”等意思，翻译时有时可不必译出。as定语从句常含有这些动词：see, know, hear, watch, remember, say, tell, show, expect, guess等，这类动词与as连用几乎成了一种固定搭配。as引导的此类从句可以置于句首、句中或句尾。如：

The famous magician Liu Qian, as we all know, is from Taiwan. 众所周知，著名魔术师刘谦是台湾人。

There is a net bar around here, as I remember. 我记得这儿附近有一家网吧。

As is often the case, girls like dolls while boys like guns. 女孩子喜欢玩具而男孩子喜欢枪，这是常见的情况。

2. which引导的从句对主句所叙述的事情进行补充说明，表明事物的状态或结果

which此时指前面主句所提到的这件事，常译为“这一点，这件事”等。这时它所引导的从句与主句之间常含有并列、因果关系。注意，它引导的从句不像as那样位置灵活，它只能位于主句的后面。如：

He changed his mind again, which made us all angry. 他又改变了主意，这使我们大家都生气了。

She tore up my photos, which (=and that) upset me.她撕碎了我的照片，这使我很不安。

3. 在从句中作定语或介词的宾语时，要用which，不用as

Jenny might come, in which case I'll ask her. 詹妮可能会来，要是那样的话我就去问她。

She graduated from a local middle school, after which she went to Beijing University. 她毕业于当地的一所中学，之后她去了北京大学。

4. 当从句的谓语动词是否定形式或含着一个复合宾语时，一般用which而不用as

He pretended not to know me, which I didn't understand. 他假装不认识我，这是我搞不明白的。

He admires everyone in his class, which I find quite strange. 他羡慕班里的每个学生，我认为太奇怪了。

【特别说明】

as引导非限制性定语从句的最大特点是位置灵活；其次，as有以下常见的，而which不具备的“固定表达”：

as we all know 众所周知    

as I can remember 正如我所记得的

as often happens 正如经常发生的那样     

as we expect 正如我们预料的那样

as you see 这一点你明白

as was expected 正如预料的那样

as can be seen 看得出来     

as may be imagined 正如可以想象的那样

as has been said above 如上所述

as we all can see 正如我们都能看到的那样

as is often the case 像常规那样

as everybody can do 正如人人都能做到的那样

区别：
1）as可指其前后主句提到的事实或情况，因此引导的非限制性从句位置比较灵活，which可以放在主句前后，也可插入主句之中；而which引导的非限制性从句只能位于主句之后：
As is known to all, fish can’t live without water.
Air, as we know, is gas.

2）在非限制性从句中，which后的be动词不可省；as而后的be动词可以省略：
She told me she won the match , which was a lie. The material is elastic, as (was) shown in the figure.

3） which在非限制性定语从句做主语时可用各类动词做谓语；而在非限制性定语从句做主语时，谓语常用连系动词，如be, seem, become等，一般不用其他行为动词：
He saw the girl, which delighted him.
He didn’t say anything at the meeting , as/which seemed very strange.

4） 如果主句中叙述的事情与从句所涉及的意向一致，多用as，用以对主句的意义进行补充；如果不一致，就用which：
She has married again, as was expected.
He broke the rules again, which was unexpected.

5）如表示“如同。。。那样，按照，正如”含义，常用as，这里as主要起与上下文联系的作用，表达说话人的看法，并指出内容，出处和根据等，常用的结构有as we know（众所周知）as often happens（正如常发生的那样）as is often the case（情况常常如此）as we all can see（正如我们看到的）
be+announced/expected/known/imagined/mentioned/said/shown/reported（正如所。。。）等。这些结构常放句首，偶尔也可以放句中或句末 ：
As is known to all, China is a developing country. Kate was late for school , as often happened.

6）在非限制性定语从句中关系代词指代主句中某一个单词时，常用which：
My brother enjoyed playing basketball , which he really plays well. Beijing , which he was born in, is our capital.

7）在非限制性定语从句中“介词+关系代词（介宾代物）”中关系代词只能用which ：
The Travel Agency, with which our company has been dealing for several
years, has opened for new branches
Air is a mixture of gases, of which oxgen forms 21 percent.

8）有时用case, point, time, situation或reason等抽象名词来总结主句的内容，可用“介词+ which +抽象名词”构成从句 ：
Ten years of hard work changed her greatly , for which reason he could hardly recognise her at first sight.
The machine may be out of order , in which case it will be repaired at once.

9）在非限制性定语从句关系代词用以代表主句中谓语的整个概念，从句中的谓语动词是否定形式时，常用which：
He can write a letter in English, which I can not.
Metal will bear beating with a hammer, which a stone willl not

10）在非限制性定语从句关系代词代表前面主句中的宾语从句时，常用which ：
He said he had passed the exam , which was untrue.

　　as 和which引导非限制性定语从句的区别
　　1. as引导的非限制性定语从句
　　1) 位置灵活，可以置于主句的句首、句中或句末；
　　2) 先行词不可是一个词，必须是整个主句或主句的部分内容；
　　3) 有“正如、像”等意思，表依据、评论（、态度、看法）等；如：
　　a. This elephant is like a snake，as anybody can see．像任何人都能看见那样，这头象像条蛇。 b. He failed in the exam, as we had expected.
　　c. Tom has passed the test, as everybody knows. 正如每个人所了解的那样，汤姆通过了考试。 【比较：Bamboo is hollow，which makes it very light．竹子是空的，这就使得它很轻。】
　　4) 常用以下谓语动词的主、被动语态：know, see, say, expect, imagine, hope, believe, announce, suggest,
　　report, point out…, 例： a. 主动（做宾）：as we all know, as you know, as everybody knows; as you see, as we can see, as we have
　　seen, as anybody can see; as was expected; as we can imagine, as we have imagined… a) As we all know, the earth is round.
　　b) He was a foreigner, as I know from his accent.
　　c) Mike, as we expected, attended the meeting．像我们所期望的那样，迈克参加了会议。 b. 被动（做主）：as is known to everybody, as is known to all; as has been expected; as is often the case
　　(with …)，as has been pointed out, as is usual with, as is reported in the newspaper… a) He is an honest man, as is known to all.
　　b) As is often the case with young people, he was overconfident.
　　c) He wasn't unconscious，as could be judged from his eyes．他并未失去知觉，这从他的眼
　　神可以判断出来。
　　2. which引导非限制性定语从句
　　1) 只能置于句中或句末（即不可置于句首，只能置于先行词之后）；
　　2) 先行词即可是一个词，也可是整个主句或主句的部分内容；是整个主句时，从句谓语动词用三单。
　　a. He seems not to have grasped what I meant, which greatly upsets me. 他似乎没抓住我的意思，这
　　使我心烦。
　　b. Liquid water changes to vapor, which is called evaporation. 液态水变为蒸汽，这就叫做蒸发。 c. He studied hard at school when he was young, which leads to his success in his later life. 3) 有“这、这一点”等意思，表事实、状态、起因、转折、让步等；如：
　　a. Bamboo is hollow，which makes it very light．竹子是空的，这就使得它很轻。
　　b. Her house, which was built a hundred years ago, stood still in the earthquake. 她的房子尽管是一百多年前建造的，但他在地震过后依然耸立。（让步） 【比较：He failed in the exam, as we had expected.】
　　c. He was late again, which made his teacher very angry. (先行词是一个句子) d. He was proud, which I dislike very much. e. He was proud, which his brother never was.
　　f. She was very patient towards the children, which her husband seldom was.
　　g. She was awarded a gold medal, which the whole family considered a great honour. 4) 常用“prep.＋which”结构
　　a. They arrived at a farmhouse, in front of which sat a small boy. b. He is a library assistant, from whom I borrowed some books. c. It is a famous school, from which he graduated 3 years ago. d. He is my son, against whom a better son does not exist．
　　e. He stood at the window, from which (/ where) he could see what was happening. f. There is a tall tree outside, under which (/where) stands our teacher.
　　5) 用“n./pron./num./adj比较或最高级 + prep.+ which/whom”结构，表示先行词的一部分
　　a. They talked about a movie, the name of which I've never forgotten．他们谈论过一部电影，我决不会忘记片名。
　　b. He paid the boy $10 for washing ten windows, most of which hadn't been cleaned for at least a year.
　　c. In Sydney the Chinese team got 28 gold medals，16.5 of which were won by women．在悉尼奥运
　　会，中国队夺得了28枚金牌，其中16．5枚是女子夺得的。 d. China has a lot of rivers, the second longest of which is the Yellow River.
　　e. China has thousands of islands，the largest of which is Taiwan．中国有数千个岛屿，其中最大的
　　是台湾岛。
　　6)
　　先行词是独一无二的事物或是专有名词时。
　　a. The moon，which doesn't give out light itself，is only a satellite of the earth．月球本身不发光，
　　它只是地球的一个卫星。
　　b. Charles Smith, who was my former teacher, retired last year. 查理去年退休了，他曾经是我的老
　　师。
　　c. Mr. Zhang, who came to see me yesterday, is an old friend of mine.
　　d. Beijing, which has been China's capital for more than 800 years, is rich in cultural and historic relics. 北京是中国八百年之久的古都,它有着丰富的文化和历史遗产。
　　e. The Nile，which used to flood every year，now runs more regularly below the dam．尼罗河年年涨洪水，现在比较正常地在大坝下面流过了。
　　f. Last year he went to Egypt，which is in Africa．他去年去了埃及，埃及在非洲。
　　g. We'll graduate in July, when we will be free. 我们将于七月份毕业，到那时我们就自由了。 7)
　　先行词被物主代词和指示代词修饰时
　　a. My house, which I bought last year, has got a lovely garden. 我去年买的的那幢房子带着个漂亮
　　的花园。
　　b. My family，which has 35 people，is a large one．我家有35口人，是一个大家庭。
　　c. This novel, which I have read three times, is very touching. 这本小说很动人，我已经读了三遍。 8)
　　先行词是表人的职业、品质、身份等名词，作定语从句的表语，主从句之间含对比的意思。 a. Mike's brother is a policeman，which he isn't．迈克的哥哥是警察，他可不是。
　　b. Her sister has become a lawyer, which she wanted to be. 她的妹妹成为了一名律师，而这是她曾经的愿
　　望。
　　9)
　　在否定意义的非限制性定语从句里（即否定意义的非限制性定语从句不可用as引导。） a. Tom has passed the test, which nobody knows. 汤姆通过了考试，但却没人知道。
　　b. He came to my birthday party，which I didn't expect at all．他来参加我的生日聚会了，这我完全
　　没有想到。
　　c. Li Ling is very clever，which Li Long isn't．李玲很聪明，李珑可不是。 d. He married her, which was unexpected. e. He married her, as /which was natural. a. Tom has passed the test, as nobody knows. ( × ) b. He married her, as was unexpected. ( × )
　　c. He came to my birthday party，as I didn't expect at all. 我完全没有想到，他来参加我的生日聚会。( × ) d.
　　Li Ling is very clever，as Li Long isn't. 李玲很聪明，李珑可不是。( × )
　　3. 互换条件：
　　1) 非限定从中的as表依据评论，which表事实状态等，但差别不大时可互换。 2) 注意位置：which引导的非限制性定语从句不能置于句首。例如：
　　a. He is quite pleased, as/which can be seen from his face. 他非常高兴，从他的表情可以看出来。 b. You always work hard, as/which everyone knows. 大家都知道，你一向勤奋学习。 c. As can be seen from his skin, he must be from Africa.
　　=He must be from Africa, which/as can be seen from his skin. d. As we have seen, oceans cover more than 70 percent of the earth. =Oceans cover more than 70 percent of the earth, as we have seen. e. As you know, Jack is an honest man. =Jack is an honest man , as you know.
　　=Jack, as you know, is an honest man. f. As is known to all, he is a hero.
　　=He is a hero, which/as is known to all.
　　=It is known to all that he is a hero. (that引导的不是定从，而是真主从) g. As we all know, smoking is harmful to one's health. (as 作宾语) =Smoking is harmful to one's health , as we all know. (as 作宾语) =Smoking, as we all know, is harmful to one' health.
　　=As is known to all, smoking is harmful to one's health. (as 作主语)
　　=It's known to all that smoking is harmful to one's health. (that引导的不是定从，而是真主从)

As引导的非限制性定语从句修饰整个主句。

1.但是主句中有否定词not，2.而as引导的从句在主句之后，那么as引导的从句不包含主句中否定的意思，所以这里的意思是“an essay in US News&World Report last May seemed to suggest that that means environmentalist concerned about uncontrolled industrial growth are anti-science"

ebedbeen关系代词as与which引导的非限制性定语从句，其先行词都可以是整个主句，指代主句的整个意思。但as和which具有不同的词义、句法和用法。

1. as引导的从句表示说话人的看法、态度、解释或评论

引导定语从句时，as仍具有“正如，像，由……可知”等意思，翻译时有时可不必译出。as定语从句常含有这些动词：see, know, hear, watch, remember, say, tell, show, expect, guess等，这类动词与as连用几乎成了一种固定搭配。as引导的此类从句可以置于句首、句中或句尾。如：

The famous magician Liu Qian, as we all know, is from Taiwan. 众所周知，著名魔术师刘谦是台湾人。

There is a net bar around here, as I remember. 我记得这儿附近有一家网吧。

As is often the case, girls like dolls while boys like guns. 女孩子喜欢玩具而男孩子喜欢枪，这是常见的情况。

2. which引导的从句对主句所叙述的事情进行补充说明，表明事物的状态或结果

which此时指前面主句所提到的这件事，常译为“这一点，这件事”等。这时它所引导的从句与主句之间常含有并列、因果关系。注意，它引导的从句不像as那样位置灵活，它只能位于主句的后面。如：

He changed his mind again, which made us all angry. 他又改变了主意，这使我们大家都生气了。

She tore up my photos, which (=and that) upset me.她撕碎了我的照片，这使我很不安。

3. 在从句中作定语或介词的宾语时，要用which，不用as

Jenny might come, in which case I'll ask her. 詹妮可能会来，要是那样的话我就去问她。

She graduated from a local middle school, after which she went to Beijing University. 她毕业于当地的一所中学，之后她去了北京大学。

4. 当从句的谓语动词是否定形式或含着一个复合宾语时，一般用which而不用as

He pretended not to know me, which I didn't understand. 他假装不认识我，这是我搞不明白的。

He admires everyone in his class, which I find quite strange. 他羡慕班里的每个学生，我认为太奇怪了。

【特别说明】

as引导非限制性定语从句的最大特点是位置灵活；其次，as有以下常见的，而which不具备的“固定表达”：

as we all know 众所周知

as I can remember 正如我所记得的

as often happens 正如经常发生的那样

as we expect 正如我们预料的那样

as you see 这一点你明白

as was expected 正如预料的那样

as can be seen 看得出来

as may be imagined 正如可以想象的那样

as has been said above 如上所述

as we all can see 正如我们都能看到的那样

as is often the case 像常规那样

as everybody can do 正如人人都能做到的那样