As的用法页PPT教学课件

1、1.1 as作介词 as作介词用来表示“以身份”或“当作”，后面跟有表示身份，职业，地位，人的特征的名词作宾语 He worked as a slave. (He was a slave.) He spoke as a lawyer. (He was a lawyer.)第2页/共31页第1页/共31页 Compare: He worked like a slave. (He was not a slave.) He spoke like a lawyer. (He was not a lawyer.)第3页/共31页第2页/共31页作介词的as常用来引入补语1).宾语的补语 a. They

2、regard him as their leader. b.He looked upon it as certain. c. I dont regard you as being dangerous. d. We consider the wire as disconnected. 注：如果补语是形容词或-ed分词，一般认为前面省略了being.第4页/共31页第3页/共31页2).主语的补语 a.The report was considered as false. b.He is better known all over the world as Mark Twain.第5页/共31页第

3、4页/共31页常用于这两种结构的动词有： acknowledge,define,describe,express,look upon,recognize,refer to,represent,serve,think of,treat, view,use第6页/共31页第5页/共31页1.2 as 作副词1).表示同等程度，数量，质量等作“一样地”解释. Paul runs fast,but I run just as fast. (I run just as fast as he does.) Tom has a lot of money but l dont have as much. (I

4、 dont have as much as he does.)第7页/共31页第6页/共31页2)用在形容词或-ed分词前： man as different from other animals man as described by scientists第8页/共31页第7页/共31页1.3 as作连词1).表示时间a.表示时间过程，作主句谓语动词所表示的动作发生的背景As they were walking , the rain began. He came up just as l reached the door.b.表示两个同时演变的情况，作“随着”解释 As one gets o

5、lder, one gets more optimistic.第9页/共31页第8页/共31页2) 表示原因 She wont be coming , as we didnt invite her.第10页/共31页第9页/共31页3).表示让步(语气比although,though强些),注意句中的语序变化： a. Cold as it was, we continued our journey. b. Much as I like ice-cream,I never eat much at time. c. Try as he would, he could not lift the ro

6、ck.第11页/共31页第10页/共31页注：表示原因的as，有时也可以用这一形式，这要从上下才能确定Young as he was,he was equal to the task.（表示让步）Young as he was,he was not equal to the task.（表示原因）第12页/共31页第11页/共31页4).表示动作的方式，作“正如”解释Leave it as it is. When in Rome, do as the Romans do .第13页/共31页第12页/共31页5)表示比较a)第一个as前可以表示倍数,程度等的词或词组来修饰.例如: Tom is

7、 twice as capable as Jim. 汤姆的能力比吉姆强一倍. Shes just as clever as her sister. 她完全像她姐姐那样聪明.第14页/共31页第13页/共31页b) 如果句中有a/an,要注意语序. 例如: It was as pleasant a day as we have ever spent. She is as good an actress as her mother.第15页/共31页第14页/共31页c) asas 结构还可以以下面的形式出现: He found riding as tiring as walking. It is

8、 as easy as falling off a long. The message is as clear as is necessary. (再清楚不过了)第16页/共31页第15页/共31页d)asas 结构中第二个as后人称代词的格的形式应和主句中与之相比较的人称代词一致. You hate him as much as I . (You hate him and I hate him too.)You hate him as much as me. (You hate him and you hate me,too) 但在口语中, 只要不引起误解,第二个as后人称代词(尤其是第一个

9、称)的主格可以用宾格表示.My sister is as tall as me.第17页/共31页第16页/共31页e) 在非正式文体中,第一个as可以省略. Your face looks (as) white as snow. You look (as)pretty as ever. Shes (as)hard as nails.第18页/共31页第17页/共31页1.4 as 构成的固定词组1.作介词用. 1)as against 比 The output amounts to ten thousand dollars as against eight thousand last yea

10、r. 2) as compared with 与对比 German, as compared with French , is difficult to learn.第19页/共31页第18页/共31页3) as for , as to 至于 Here I am. As for the others, theyll arrive late. As for me, I am satisfied.There is no doubt as to who will be elected.注: as for后不跟名词从句;所构成的短语一般放在句首,和前面提到的人或事物有关.as to后可跟名词从句;所构

11、成的短语的位置不固定,常用于书面语体.第20页/共31页第19页/共31页4) as from 自起The contract shall be in effect as from January 1,1992.5)as a result of 由于.的结果 As a result of the heavy snow, all the traffic was stopped.6) as regards 至于 As regards that , I havent decided yet.第21页/共31页第20页/共31页2.as构成的固定词组作副词1).As above 如上The rule h

12、as been explained as above.2). As a matter of 事实上 As a matter of fact, he wasnt present at the meeting.3).as a whole 就整体来说As a whole the relocation seems to have been beneficial.4).as follows 如下Their names are as follows.第22页/共31页第21页/共31页5).as good as 和几乎一样,实际等于 Were as good as ruined.6).as such 其本

13、身, 照其资格 He was a guest, and was treated as such.7).such as to 这样的以至 His kindness was such as to make us all love him.8).as yet 尚,至今还(用于否定句) I have received no answer from him as yet.第23页/共31页第22页/共31页3.as构成的固定词组作关系代词1).as go 就一般情况来说He is quite good, as boys go.2).as it is, as it was 事实上, 按现状 I thoug

14、ht conditions would get bettet, but as it was, they were getting worse.3).as it were好象是He became, as it were, a kind of hero from a strange land.第24页/共31页第23页/共31页4.As构成的固定词组作连词1).according as根据, 按照而You may go or stay,according as you decide.2).in as (so)far as 根据程度 In as (so)far as we can believe t

15、he facts,we will use them.第25页/共31页第24页/共31页 as作连词与 when ,while 区别1. 作当的时候,引导时间状语从句。注意与when、 while的用法区别。 when作当的时候解,可以指较短的(一点)时间,也可指一段时间。如: When he was at college, he could speak several foreign languages. When the clock struck twelve, all the lights in the street went out. while常表示一段较长的时间或一个过程,强调主句

16、谓语动词与从句谓语动词同时发生。如: Work while you work. Play while you play. 第26页/共31页第25页/共31页 但属下列情形时,只用as, 而不用when或while。 A) 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. He looked behind from time to time as he went forward. B)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

17、 and more worried. As children get older, they become more and more interested in the things around them. 第27页/共31页第26页/共31页C)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.D) 后接名词表示某一年龄段时,用as。如:As a young man, he was acti

18、ve in sports. 第28页/共31页第27页/共31页 2. as=since, 作既然、由于解,引导原因状语从句,常用来表示已为人们所知或显而易见的原因或理由。如: As / Since youre not feeling well, you may stay at home. As he wasnt ready in time, we went without him. 3. as=in the way that, 作像、按照的方式解,引导方式状语从句。如: He speaks English as Americans do. Remember, you must do everything as I do. 第29页/共31页第28页/共31页