英语中比较结构用于形容词和副词， 因为只有形容词和副词具有原级、比较级和最高级。考试中主要测试比较结构的特殊用法。
一、比较结构考点
考点一： 原级比较一般用 as … as ; not as … as ; the same … as
特殊结构 A is to B what / as X is Y ; A+倍数或几分之几 as + adj。 / adv。 + as +B。
The work is not as difficult as you think。
Air is to us as water is to fish。 我们与空气的关系就像鱼和水的关系。
This book is twice as thick as that one。
考点二：比较级常用结构 A + 比较级 + than + B
特殊结构：the more … the more (越…越…)； more and more （越来越…）
This question is less difficult than that question。 (比较对象为彼此独立的人或事物)
Iron is more useful than any other metal。 (比较对象具有所属关系， 有最高级含义)
The city is becoming more and more beautiful。
考点三：以拉丁文-ior结尾的含有比较意义的形容词后接to 而不是than，(参见形容词部分) 这些词是：
superior， inferior ， senior ， junior ， major ， minor， anterior， prior， posterior
He is three years senior to me。
This type of computer is superior to that type。
考点四：最高级用于三者以上的事物之间的比较。比较的范围表示地方用介词in; 表示所属关系和人物比较用介词 of。( 即the +最高级＋in /of …)
The Yangtze River is the longest river in China， but it is the third longest river in the world。
The youngest member of the family is most successful。
Of all forms of energy， electricity is most widely used。
考点五：在 more … than 结构中，than 有时可看作关系代词，相当于than what…。
This hotel is far more luxurious than is necessary。
There are more wonders in heaven and earth than are dreamt of。
天地间的奇迹比人们所梦想的要多得多。
The medicine is more effective than is expected。
考点六：英语中有一小部分表示绝对意义的形容词没有比较级和最高级。如：
dead， deaf， empty， total， whole， perfect， complete， right， wrong， equal， daily false， final
absolute， alone， round， pregnant， square， supreme， unique， straight， eternal， unanimous
考点七：几组由 “more than ；more … than” 和“no / not ＋ 比较级”等组成的固定结构及其含义
more than 意为：“不仅仅是，非常，十分”等，用法和意义较多
more …than 意为：“与其说…不如说，不是…而是”
What we are doing today is more than donating some money。
今天我们所做的不只是捐一些钱。
Their action was more than justified。 他们的行动是完全有理由的。
He is more brave than wise。 他有勇无谋。
The book seems to be more a dictionary than a grammer。
这本书看起来与其说是一本语法书，不如说是一本词典。
no more than 强调少，意为“只有，不过，仅仅”
not more than 客观叙述，意为“不超过”
He has no more than five dollars on him。
他身上仅有5美元。（强调少）
He has not more than five dollars on him。
他身上带的钱不超过仅有5美元。（强调数额少于5美元）
no more … than 意为“A与B都不…；…不，…也不”
not more … than 表示程度上的差异
He is no more diligent than you。
他不勤奋，你也不勤奋。（两人都不勤奋）
He is not more diligent than you。
他没有像你那样勤奋。（两人都勤奋，但你更勤奋）
no less than = as much as 意为：“竟有…之多，多达”，强调多
not less than 意为“不少于，至少”，为客观的描述
no less … than 前后均为肯定，意为：“正是，和…一样， 多达，应有…之多”
His son has read no less than 50 English books。
他的儿子竟然读了50本英文书。（强调多）
His son has read not less than 50 English books。
他的儿子读了不少于50本英文书。（不强调多或少）
The middle-aged man was no less a person than the new minister。
这位中年人正是新来的部长。
Her voice is no less sweet than it used to be。 她的歌声和以前一样甜美。
考点八： 英语中关于倍数的常见表达法
1。 倍数 + 单位名词N + of 其中N表示比较的内容，如：weight， size， age等
This room is three times the size of that one。
2。 倍数 + what-clause
They turn out 400 kinds of products with a total value more than 40 times what it was in 1980。
3。 倍数 + that / those of = as much as …
His weight is three times that of mine。
4。 倍数 + as … as
This room is three times as large as that one。
5。 倍数 + more + than
This room is three times larger than that one。
6。 –fold
From 1980-1990， Danube shipping increased more than sixfold。
