语法专题（七）比较结构
一、比较等级和比较结构
比较等级是指形容词和副词有原级、比较级和最高级之分。而比较结构是指运用形容词和副词的级别，对两种或两种以上的事物进行比较的短语结构。根据比较级别可以分为三类：一是表示某物和某物一样；二是表示某物比另外某物更加怎么样；三是表示某物最怎么样。下面我们分别来看表示这三种比较的英语结够有哪些。
二、三种比较结构
（一）原级：as …as结构, 具体在句子中，就有两种应用形式：
A is as +adj as
B 或者：A do B as + adv + as
C (do).
Mary is as tall as Betty.
I drove as carefully as Tom did.
好，我们来看一下这种结构的一些变化形式：
1）否定式：A is not as/so + adj + as B；或 A do not do B so/as + adv + as C (do).
Mary is not so tall as Betty.
I did not drive as carefully as Tom did.
2) as +many/much + 名词+ as
There are as many students in our class as in their class.
We have as much snow this year as last year.
3) A is as + adj + a/an + 名词+ as B
Mary is not as beautiful a girl as Betty.
I just want to read as interesting a book as that one.
4) A is a/an + 名词+ as + adj + as B.
实际上这是将上面第3）种的名词提前，这样as + adj + as B就变成了后置定语。
Mary is not a girl as beautiful as Betty.
I just want to read a book as interesting as that one.
5）A is as+adj(1) as A is+adj (2).
注意：（1）这是as….as…结构比较特殊的用法，是指将同一事物就其两个不同的方面进行比较, 所以结构中的两个形容词是不同的。
Mary is as beautiful as she is clever.
= Mary is beautiful, and she is clever too.
= Mary is both beautiful and clever.
= Mary is not only beautiful but also clever.
This book is not as intersting as it is instructive.
= This book is instructive, but it is not interesting.
（2）否定形式中的一种特例：A is not so much a/an B as (A is) a C.
翻译是：与其说A是B, 不如说他是C.
He killed many innocent people. So he was not so much a hero as a killer.
他杀了许多无辜百姓。所以与其说他是英雄，不如说他是杀人犯。
6) 带有修饰语的as….as….结构。
A is almost/exactly/nearly/just/quite/not/not half/half/twice/three times+ as +adj as B
A do
B almost/exactly/nearly/just/quite/not/not half/half/twice/three times as + adv + as C
I am just half as tall as Y ao Ming.
Y ao Ming is twice as tall as me.
I don’t eat half as much as he does.
He doesn’t work half as hard as me.
I work twice as hard as he.
（二）比较级：more…than结构，具体在句子中，就有两种应用形式：
A is …er than B( A is more + adj原级+ than B)，或者：
A do
B …er than
C (A do B more +adv原级+ than C.).
Mary is taller than Betty.
Mary is more beautiful than Betty.
Mary studies harder than Betty.
I drove more carefully than Tom did.
下面我们来看该结构的各种变形：
1)否定形式
A is not…er than B( A is not more + adj原级+ than B) 或者：
A don’t do
B …er than
C (A don’t do B more +adv原级+ than C.).
Mary is not more beautiful than Betty.
Mary does not study harder than Betty.
注意：这里可以用less…than来表示more…than的反义，但less…than听起来不自然，用as…as或more…than更加普通。如：
Mary is less beautiful than Betty.
= Mary is not as beautiful as Betty.
= Betty is more beautiful than Mary.
2)more/less/fewer + 名词+than
There are more students in our class than in their class.
He makes more money in a month than I do in a year.
再将上面两句话换种方式说：
There are less (=fewer) students in their class than in ours.
I make less money in a year than he does in a month.
3) A is + a/an…er/more + adj原级+ 名词+ than B.
Mary is a more beautiful girl than Betty.
Tom’s house is a larger house than my house.
= Tom has a larger house than mine.
4) A is + a/an +名词+…er/more + adj原级+ than B.
该结构就是在上面第3）种的基础上将名词提前，这样…er/more + adj原级+ than B就变成了后置定语。如：
Mary is a girl more beautiful than Betty.
Tom’s house is a house larger than mine.
= Tom has a house larger than mine.
5）A is more+adj(1) + (a/an+名词) + than +adj (2).
注意：这是more….than…结构用来将同一事物就其两个不同的方面进行比较, 所以结构中的两个形容词是不同的。翻译成：与其说A（2），不如说它（1）。如：Mary is more beautiful than clever. 与其说玛丽聪明，不如说她漂亮。
= Mary is less clever than beautiful.
Mary is more a beautiful girl than a clever girl.
= Mary is less a clever girl than a beautiful girl.
6）带有修饰语的more…than…结构
