常用的as句型.doc

常用的as句型 as是英语中用得非常广泛而且极其活跃的一个词。它可以作介词、副词、从属连词和关系代词用，还可以同其它的词搭配，构成一些固定的词组和句型，表达各种意思。本课仅就as构成的一些常用句型作些介绍。1. 时间状语从句中的as as引导时间状语从句，表示主句动作和从句动作同时发生，可译为“随着”或“一边.一边”；“当.时候”，例如： As days go by , it becomes colder and colder. （随着）We get wiser as we get older. She was reading something as she was waiting for the bus to come . （当.时候; 一边.一边）2.原因状语从句中的asas 引导原因状语从句，表明显的原因或已知事实。例如：As Im so ashamed of my body, Im trying to lose weight.We had to walk all the way, as we had no money for fares.As it was getting very late, we soon turned back.3.让步状语从句中的asas 引导的让步状语从句以部分倒装的形式出现，从句中的表语、状语或谓语部分的实义动词要前置到句首。若作表语的名词前有冠词，需去掉冠词。例如：Tired as we were, we didnt give up.（形容词作表语置于句首）Child as she was , she was able to stand on her own feet.（名词作表语置于句首）Try as he may, he couldnt open the door. （谓语部分实义动词try置于句首）Much as I like it, I cant buy it, for it is too expensive for a student. （副词作状语置于句首）4.比较状语从句中的asas在比较状语从句中通常与另一个as连用，构成句型asas，意为“和.一样”，表同级比较。使用时要注意第一个as为副词，第二个as为连词，其基本结构为：as+ adj./ adv. +as。例如：This film is as interesting as that one（is）.Your pen writes as smoothly as mine (writes).He is as good a player as his sister.其否定式为not as/so +adj./ adv. +as。例如：This dictionary is not as/so useful as you think.若有修饰成分，如twice, three times, half, a quarter等，则须置于第一个as之前。例如：Your bag is twice as expensive as mine（is）.5.方式状语从句中的asas引导方式状语从句位于主句之后。例如：Do as you are told to, or you will be fired. We do farm work as the old peasant teaches us.6.定语从句中的as(1) as引导限制性定语从句，一般与the same 或 such连用，指代前面的先行词，在从句中充当主语、宾语或表语。He is such a person as is respected by all of us.(作主语)The lady wore the same dress as I bought yesterday.(作宾语)He is not the same man as he used to be.(2) as 引导非限制性定语从句，指代整个主句，位置比较灵活，可位于主句前，也可位于主句后，还可位于主句中间。例如：She is a fine singer, as her mother used to be .(作表语)As was reported, the old lady injured in the traffic accident was in hospital . (作主语)The earth, as we know, moves around the sun.(作宾语)As is known to us, knowledge is power.7.并列句中的as如果并列句表“也是如此”之意，可用as+be/助动词/情态动词，如：Her mother is tall and as is she.I often go to school by bi