as引导的定语从句PPT课件

As 引导的定语从句专讲一."a s”可用作关系代词引导定语从句(同which)代替整个句子或一件事，引导非限制性定语从句（在从句中作主语、宾语或表语）意为“正如……，就像……，据……”(从句位置可置于主句之前或之后，有时也可作为插入语置于句中，一般用逗号和主句隔开，但which只能用在主句之后)这种用法常见于以下这些结构:1.在从句中做主语：as can be seen / as is（well）known / as may be imagined / as often happens/ as has been said before / as was mentioned above / as is often the case2. 在从句中做宾语：as we know / as we can see3. 在从句中做表语：as indeed it isEg.1.As is well known, great changes have taken place in China.Great changes, as is well known, have taken place in China.众所周知，中国发生了巨大的变化。

( as在定语从句中作主语。

)2.This experiment is very simple，as indeed it is.实验非常简单，事实上也确实如此。

(as在定语从句中作表语。

)注意：She married him，which was unexpected.She married him, as（was）unexpected.（as作主语，代替前面的句子)在as所引导的非限制性定语从句中，如果运用的是被动语态结构，be动词可以省略；但which 没有此用法，be动词不可省。

二．as除了代替整个句子，也可以代替主句中一个特定的词They were satisfied with this decision，as was agreed beforehand.( as在定语从句中作主语, 其先行词是this decision)I never heard such stories as he tells. ( as在定语从句中作宾语，先行词是such stories.) The place doesn't look the same as it was before liberation.( as在定语从句中作表语，先行词是same)在这种用法中它经常和such, so, the same等词搭配使用；且当先行词中有such, so, the same 等词修饰时，关系代词通常必须用as。

关系代词AS的用法关系代词as引导定语从句时，既可以单独使用，也可以与其他词连用，其用法要比that 和which更为复杂。

同学们要下点功夫哦!AS作关系代词,可以用来引导定语从句:限制性定语从句和限非制性定语从句一、AS引导限制性定语从句AS引导限制性定语从句时,通常和such,the same,as(so)等连用,构成如下结构:such...as/such as,the same...as/the same as, as(so)...as等结构,在从句中可作主语,宾语和表语。

...as/such as意为“...的那种...,像那样的”，such...as/such as引导限制性定语从句时,既可指人,也可指物。

such用于名词之前时,具有形容词性质；such单独使用(即后面不接名词)时,具有代词性质。

Don’t trust such men as praise you to your face.(as作主语)不要相信那种当面吹捧你的人。

You should read only such books as you can understand without much difficulty.(as作宾语)你应当只读那些你读起来不太难懂的书。

Associate with such as will improve your manners.(as作主语)要和能改善你的言行的那种人结交。

same...as/the same as意为“与...同样的”,和such一样,the same既有形容词作用,又有代词性质。

We have arrived at the same conclusoin as they have.(as作宾语)我们已得出和他们同样的结论。

比较:the same...as和the same...that不同,前者是“同那一个相似”,后者是“正是那一个”。

如：This is the same watch as I lost.这同我丢的那块表一样。

之邯郸勺丸创作as是考研英语中十分罕见的单词,用法灵活多样,是英语中最经常使用的词汇之一.as主要有两种词性,辨别为介词和连词.as作为介词时,用法和语义较单一,其含义为“作为”.但是as作为连词词性时,其用法和功效较多,可以引导各类从句,而对其所引导的从句类型的识别也就成为了as理解的难点.在此对as引导各类从句进行汇总,并对各类从句的特点给出具体总结.一、as引导定语从句as引导定语从句时,既可以引导限定性定语从句,又可以引导非限定性定语从句.区分as引导定语从句和其它从句的关头特征是：as引导定语从句时在从句中做成分,通常做主语或宾语.1、as引导限定性定语从句.如从句所修饰的名词前有such、the same、as出现,后面的定语从句将由as引导,形成such...as,the same...as,as…as这样的固定结构,译为“和……一样”.例1：I never heard such stories as he told.我从未听过他所讲的那样的故事.例2：He’ll repeat such questions as are discussed in the book.他将重答信中讨论过的问题.例3：They made the same mistake as others would have made on such an occasion.他们犯了和其他人在这种场合下会犯的同样错误.2、as引导非限定性定语从句.as引导非限定性定语从句,往往指代一整句话,通常暗示“正如”的意思.as引导的非限制性定语从句位置相对比较灵活,可以位于先行词之前、之后或中间.例：As is known to everybody, the moon travels round the earth.众所周知,月亮绕着地球转.二、as引导时间状语从句as引导时间状语从句多用于口语,强调“同一时间”或“一先一后”,有时还有“随着”的含义.例1：As I was going out, it began to rain.当我出门时,开始下雨了.(as强调两个动作紧接着产生,不强调下雨的特定时间.)例2：As time goes on, he will understand what I said.随着时间的推移,他会理解我所讲的话.三、as引导原因状语从句as暗示“因为”,与because相比,较口语化,所表达的原因语气较弱,所表的原因比较明显,或是已知的事实.例1：As the weather is so bad, we have to delay our journey.因为天气太糟糕,我们不克不及不推迟旅行.例2：Any new source of energy will be very welcome, as there is already a shortage of petroleum.任何新型能源都将大受欢迎,因为石油已经出现短缺.四、as引导方法状语从句as暗示“依照”,“以……方法”,“像……一样”,“正如”.例：Do as the Romans do when in Rome. 入乡随俗注：as在引导方法状语从句时,还常出现在一个固定的类比结构中：(just) as …, so….这一句型暗示类比,基本含义是“正如……,所以……”.例：Just as virtue is its own reward, so is vice its own punishment.善有善报,恶有恶报.五、as引导让步状语从句as可以暗示“尽管”,“虽然”,引导让步状语从句,但必须组成倒装.让步状语从句倒装规则有两类：1、形容词/副词/分词/名词(无冠词)/介词短语等+as+主语+谓语动词,主句.例1：Much as I like you, I couldn’t live with you.我尽管很喜欢你,却不克不及和你在一起生活.例2：Child as he is, he knows to help others.尽管他是个孩子,他懂得帮忙他人.2、动词原形+as+主语+助动词(may/might, will/would,can/could, do/does/did),主句.例：Try as we may, we cannot sense directly the television signal sent out from the broadcast station.尽管我们费了很大的劲,也无法直接觉察发射台收回的电视信号.六、as引导比较状语从句as引导比较状语从句,其基本结构是as…as.前一个as是副词,后一个as是比较状语从句的连词.否认结构为not somuch … as ….例1：Small as it is, the ant is as much a creature as are all other animals on the earth.尽管蚂蚁很小,但是它同地球上的任何其他动物一样,也是一种动物.例2：It was not so much the many blows he received as the lack of fighting spirit that led to his losing the game.与其说是他受到了许多打击,还不如说是缺乏斗志使他输掉了角逐.。

as引导定语从句的用法as 引导非限制性定语从句，可放在主句之前，或者主句之后，甚至可以切割一个主句；which引导的非限制性定语从句只能放在主句之后。

另外，as有“正如……，正像……”的意思(1) As is known to all, China is a developing country.(2) He is from the south, as we can see from his accent.(3) John, as you know, is a famous writer.(4) He has been to Paris more than several times, which I don’t believe.================================As 的用法例1. the same…as；such…as 中的as 是一种固定结构, 和……一样……。

I have got into the same trouble as he (has).例2. as可引导非限制性从句，常带有'正如'。

As we know, smoking is harmful to one's health.As is known, smoking is harmful to one's health.As是关系代词。

例1中的as作know的宾语；例2中，它充当从句的主语，谓语动词know要用被动式。

一、“as / which”特殊定语从句的先行成分1. 形容词或形容词短语作先行成分, 具有形容词意义的介词短语也可以充当先行成分，如：My grandmother’s house was always of great importance to me, as my own is.在一定的语言环境里，有些名词可以具有形容词的性质。

这些名词主要是那些表示人的身份、职业、状态的名词。

as引导的定语从句什么是定语从句？定语从句是英语语法中的一种句子结构，用来修饰或限定一个名词或代词，增加其具体信息或描述。

定语从句通常由关系代词或关系副词引导，其中，以as引导的定语从句是一种常见的结构。

as引导的定语从句用法as引导的定语从句一般用来修饰前面的名词，承担定语的作用，并且在从句中充当主语或宾语。

1.主语的用法以as引导的定语从句作为名词的主语时，一般紧跟在名词后面，由as引导从句。

例如：•I met a girl as was from Germany. （我遇到了一个来自德国的女孩。

）•I don’t know if there is anyone as can help us. （我不知道是否有人能帮助我们。

）2.宾语的用法以as引导的定语从句作为名词的宾语时，一般出现在名词后面，并且被一个动词或介词所引导。

例如：•Do you know such a person as I mentioned? （你知道我提到的那个人吗？）•I need a book as has a blue cover. （我需要一本蓝色封面的书。

）as引导的定语从句的特点与其他引导词相比，as引导的定语从句具有以下特点：1.引导词as在从句中充当主语或宾语，常常与主句或从句中的其他成分形成对应关系，使句子结构紧凑。

2.as引导的定语从句往往与先行词之间存在更加明显的逻辑关系。

3.as引导的定语从句通常用于口语或非正式场合，比较少用于正式写作。

注意事项在使用as引导的定语从句时，需要注意以下事项：1.as引导的定语从句常常用于非正式场合，如口语交流或日常对话。

在正式的书面文体中，建议使用which、that或关系副词where来引导定语从句。

2.as引导的定语从句常常用于限定性定语从句，即从句对先行词进行限定，并且与先行词的意义关系密切。

如果使用非限定性定语从句，应使用关系代词which引导从句。

3.在as引导的定语从句中，从句部分对于整个句子的完整性非常重要，不可省略或替换成其他句子成分。

As引导的从句1. 引导时间状语从句，作"当……的时候"，其特点为：1) 用于表示同一个人的两种动作交替进行，指"一边……,一边……"。

如:The girl dances as she sings on the stage. 这个孩子在舞台上载歌载物。

He looked behind from time to time as he went forward. 他边走边不时地回头看。

2)表示两个同步发展的动作或行为,译为"随着……"。

如：As time went on / by, she became more and more worried. 随着时间的流失，她越发担心。

As children get older, they become more and more interested in the things around them.3)表示两个短促行为或事件几乎同时发生。

如:I thought of it just as you opened your mouth.Just as the flying worm hit her face, she gave a loud cry.4) 后接名词表示某一年龄段时，用as。

如:As a young man（=When he was a young man）, he was active in sports.注意与when、 while的用法区别：1）when作"当……的时候"解，可以指较短的(一点)时间，也可指一段时间从句的动作可以与主句的动作同时发生，也可以先于主句的动作发生。

如：When he was at college, he could speak several foreign languages. 他上大学时能讲好几门外语。

When the clock struck twelve, all the lights in the street went out. 当钟敲响12点时，街上所有的灯都熄灭了。

as引导的定语从句关系代词as在从句中即可指认也可指物，可做主语、宾语、表语。

常用语一下几种情况：1．the same+名词+as....：such+名词+as....意为“和...一样”This is the same book as I bought yesterday.Tom is not the same man as he was.These houses are sold at such a high prize as people expected.He is such a kind teacher as students like.2．先行词为整个句子，常用逗号分开，可置于句首、句中或句末.As is well known to us all, we should be equal before laws.Xu beihong , as we all know, was a great painter.She was late for school again , as we expected.My grandfather is fond of talking about the old days, as is often the case with old people.Just as Edison put it，genius is 99 percent sweet and 1 percent inspiration．As you can imagine, getting burnt can lead to very serious injuries.常见的习惯用语：as you see/know, ......as can be seen,...as everyone knows,.... as the old saying goes,.... as is often the case,...as we expected , .....as was expected , ..... as has been said before,....as was mentioned above, .....as sb put it,...as was reported in the newspaper,... as you can imagine,...as the study suggests,...填空练习1.She opposed the plan, _______we expected.2．_______is said above, the new technology will be of great use.3．We，_______ was planned, got there before eight.4．I have got into the same trouble _____ he has.5．Journey to the west is such an interesting book_____ all children want to read.6．______ he often puts it, university education determines one’s future.7．_______the study suggests, hugs , _______ can help us get away from negative feelings , are of great benefit for us .1。

as定语从句的用法一：as可以代替整个句子或一件事，引导非限制性定语从句，在从句中作主语、宾语或表语，意为“正如……，就像……，据……”；从句位置可置于主句之前或之后，有时也可作为插入语置于句中，一般用逗号和主句隔开。

as的这种用法常见于以下这些结构:as we can see, as can be seen, as we know, as is（well）known, as may be imagined, as often happens, as has been said before, as was mentioned above, as is often the case, as/indeed it is…例:As is well known，great changes have taken place in China. 或Great changes, as is well known, have taken place in China.众所周知，中国发生了巨大的变化。

( as在定语从句中作主语。

)This experiment is very simple，as indeed it is.实验非常简单，事实上也确实如此。

(as在定语从句中作表语。

)注意：①which在引导非限制性定语从句时，也有和as一样的功能，可以代替整个句子，但which只能用在主句之后。

②在as所引导的非限制性定语从句中，如果运用的是被动语态结构，be动词可以省略；但which没有此用法，be动词不可省。

例如:She married him，which was unexpected.＝She married him as（was）unexpected.她嫁给了她，这一点大家都没有料到。

（作主语，代替前面的句子；用which时was不可省。

）二as除了代替整个句子，也可以代替主句中一个特定的词。

as在它引导的定语从句（限制性或非限制性）中可以充当主语，宾语和表语；在这种用法中它经常和such, so, the same等词搭配使用；且当先行词中有such, so, the same等词修饰时，关系代词通常必须用as。

as在定语从句中是关系代词，可做句子成分。

但在上述两个句子中，as只是在引导定语从句而已，不作句子成分。

as 引导非限制性定语从句，可放在主句之前，或者主句之后，甚至可以切割一个主句；which 引导的非限制性定语从句只能放在主句之后。

另外，as有“正如……，正像……”的意思(1) As is known to all, China is a developing country.(2) He is from the south, as we can see from his accent.(3) John, as you know, is a famous writer.(4) He has been to Paris more than several times, which I don’t believe.================================As 的用法例1. the same… as；such…as 中的as 是一种固定结构, 和……一样……。

I have got into the same trouble as he (has).例2. as可引导非限制性从句，常带有'正如'。

As we know, smoking is harmful to one's health.As is known, smoking is harmful to one's health.As是关系代词。

例1中的as作know的宾语；例2中，它充当从句的主语，谓语动词know要用被动式。

一、“as / which” 特殊定语从句的先行成分1. 形容词或形容词短语作先行成分, 具有形容词意义的介词短语也可以充当先行成分，如：My grandmother’s house was always of great importance to me, as my own is.在一定的语言环境里，有些名词可以具有形容词的性质。