比較狀語從句是主從復合句，所以它由兩部分構成：主句和狀語從句。主句和從句存在著比較關系。一般模式為：主句+連詞+比較狀語從句。常用連詞或結構有：as；as …as, not as/ so … as；than；:the more … the more … ; just as …, so…; A is to B what /as X is to Y; no … more than; not A so much as B
1.比較
同級比較： as...as 引導的比較狀語從句；as 引導的比較狀語從句；not so/as...as "引導的比較狀語從句；as many/much a引導的比較狀語從句。
例如：She is as bad-tempered as her mother.
There are almost as many definitions of history as there are historians.有多少歷史學家，就有多少歷史學的定義。
That's not so/as simple as it sounds.那件事情不像聽起來那么簡單。
不同級比較： than引導的比較狀語從句；more...than引導的比較狀語從句；less...than引導的狀語從句。
例如：You look younger than you are. 你看上去比你的實際年齡要年輕。
2.倍數：表達倍數也是一種比較。常用：是......倍，可以用N times as much as來表達;多......倍，可以用”more than/less than”來表達；是百分之幾，則可以用N%來表達。
The house is three times as big as ours.
There are only half as many fisheries as there were 15 years ago. 如今的漁場數量僅是15年前的一半。
其他：the..., the...引導的比較狀語從句；not …so much as引導比較狀語從句；“not….any more than”比較狀語從句；“no more ….than”引導的比較狀語從句；no less than. 引導的狀語從句；not any less than”引導的狀語從句。
如：Mary is no more diligent than Tom.就意為Mary和Tom都不勤奮。
The more you study, the more knowledge you can get. 你學的知識越多，你的知識越豐富。
The great use of a school education is not so much to teach you things as to teach you the art of learning.學校教育的重大作用，與其說是交給你東西，不如說是交給你學習的藝術。
省略和替代：
比較狀語從句中，若存在相同性質的比較對象，會出現表達的重復，所以會使用替代和省略。
例如：James enjoys the theater more than Susan does .(動詞替代）
Contrast may make something appear more beautiful than it is when seen alone.（it is后省略了 beautiful）。
