英语中比较结构使用于形容词和副词， 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和特殊用法。
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.