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 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， 含有最高级含义)
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. 这些词是：
superior, inferior , senior , junior , major , minor, anterior, prior(在。。。之前) ,
posterior (在。。。之后)
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，所以比较的范围自然是少不了。一般表示地方用介词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…
There ought to be less anxiety over the perceived risk of getting cancer than exists in the public mind today. (Than = than what…)
人们不应该像今天这样担心害怕患上癌症。
There are more wonders in heaven and earth than are dreamt of. ( than=than what…)
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”等构成的惯用句式及其含义。
more than 其含义为:“不仅是，非常，十分”等，用法和意义较多。
more …than 其含义可以是:“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含有消极否定的意思，可译为“A与B都不…，不… 也不”
not more … than 含有积极、肯定的意思，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”，可观地描述
no less … than 前后均为肯定，含有惊奇的感情色彩。可译为：“是…是，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。