as用法第1讲
首先,as可以作介词
as作介词用以表示“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。
例如:
He worked as a slave.(He was a slave.)
He spoke as a lawyer.(He was a lawyer.)
比较:
He worked like a slave.(He was not a salve.)
He spoke like a lawyer.(He was not a lawyer.)
作介词的as常用来引入补足语:
(1)宾语补足语
例如:
They regarded him as their leader.
He looked upon it as certain.
I don't regard you as being dangerous.
We consider the writer as disconnected.
注:如果补足语是形容词或-ed分词,一般认为前面省略了being。
(2)主语补足语
例如:
The report was considered as false.
He is better known all over the world as Mark Twain.
常用语这一类结构的动词有如下一些:
acknowledge,define,describe,express,look upon,recognize,refer to,represent,serve,think of,treat,view,use等。
as用法第2讲
其次,as可用作副词
(1)表示同等程度、数量、质量等作“一样地......”解释。
例如:
He runs fast,but I run just as fast.(=I run just as fast as he does.)
Tom has a lot of money but I don't have as much.(=I don't have as much as he does.)
(2)用在形容词或-ed分词前。
例如:
man as different from other animals
man as described by scientists
as用法第2讲
再次,as可用作关系代词
(1)在the same...as“像......一样的......"和such...as”像......那样的......”结构中,as引导限制性形容词从句。
例如:
He is just the same as he used to be.
Such passengers as survived the explosion were drowned.
(2)as(=which)引导的非限制性形容词从句,可以出现在句首、句中或句尾。
例如:
She is a teacher,as is clever from her manner.
Water,as is known to all,is a liquid.
类似as you know的从句还有:
as everybody knows,as I see,as I have said,as I am told,as you may remember,as you may have heard,as you say等。
注意:区别形容词从句as seems和副词从句as it seems:
例如:
He is the best candidate,as seems possible.(as指主句)
He is the best candidate,as it seems.(it指主句)
as用法第2讲
小结:以上是关于as的三大用法小结,分别从as用作介词、副词和关系代词三个方面进行了小结,希望大家能够认真复习巩固。咱们下一期接着as用法的第2讲内容。,