as简单之至的一个单词,用法却非常复杂.

as用法一.两种事物的同种属性进行比较,as中间是形容词或副词,结构如下:

事物A+谓语+as/so+adj(形容词)/adv(副词)+as+事物B 

注:肯定句用as,否定句用as/so均可. 它们是adv(副词)用来修饰其后的adj(形容词)/adv(副词),as是连词用来连接事物B.

例句分析:

1.She is as beautiful as her sister.   她和她姐姐一样漂亮.

造句步骤1.先写句子 她漂亮 She is beautiful.肯定句在形容词前加as,所以句子为:She is as beautiful.

    步骤2.找比较对象她姐姐 her sister,并在其前加as,所以为:as her sister

    步骤3.将1和2连起来完整句子为 She is as beautiful as her sister.

2.She doesn't study as/so hard as her sister.她不如她姐姐学习用功.

造句步骤1.先写句子 她学习不用功 She doesn't study hard. 否定句在副词前加as/so,所以句子为:She doesn't study as/so  hard.

    步骤2.找比较对象她姐姐 her sister,并在其前加as,所以为:as her sister

    步骤3.将1和2连起来完整句子为 She doesn't study as/so hard as her sister.

as用法二.事物A+谓语+倍数+as/so+adj(形容词)/adv(副词)+as+事物B 

倍数词:once,twice,three times,four times...half , 基数词+序数词(基数词大于1,序数词后加+s)来表示几分之几, 三分之一one third,三分之二two thirds,

例句  My books are twice as many as yours.我的书是你的两倍多.

as用法三.两种事物的同种属性进行比较,as中间是名词,结构如下:

事物A+谓语+as+adj(形容词)+a+n(名词)as+事物B

例句分析:

She is as clever a child as my sister.  她和我妹妹一样是聪明的孩子.

造句步骤1.先写句子 她是个聪明的孩子.She is a clever child .as只修饰形容词,不能修饰a,所以a,clever交换位置,as放在clever前,所以句子为:She is as clever a child

    步骤2.找比较对象我妹妹 my sister,并在其前加as,所以为:as my sister

    步骤3.将1和2连起来完整句子为:She is as clever a child as my sister.

as用法四.主语+谓语+as+adj/adv+as one can(could)/possible.尽可能......

例:I read the book as carefully as I can.我尽可能认真地看这本书.

注:以上几种用法均是形容词,副词原级比较从句,事物B都省略了与事物A后相同谓语部分,one can 后也省略了与谓语相同部分.

as用法五.同种事物的两种不同属性,则无比较含义,只说明这种事物具有两种属性,肯定句意为又......又......,不但......而且......,  ......而,却......句子结构为:

句子A+谓语+as+adj(形容词)+as+句子B

例句分析:

1.She is as clever as she is beautiful. 她既聪明又漂亮.

造句步骤1.先写句子 她聪明 She is clever.肯定句在形容词前加as,所以句子为:She is as clever

    步骤2.再写句子她漂亮 She is beautiful.在句子前加as,所以句子为:as she is beautiful

    步骤3.将1和2连起来完整句子为 : She is as clever as she is beautiful.

2.We are as poor as we are happy. 我们穷但我们快乐.

3.She is as beautiful as her sister is ugly.她长得漂亮,她妹妹长得丑.

造句步骤同1.不再赘述.