比较状语从句
比较状语从句由连接词than，as…as, not so…as, less…than等等构成。
一、比较状语从句较麻烦的三种情况：
1、 As, than后面可以跟任何一个句子，一个短语或一个单词，并且可以省略。
The problem is more complicated than I thought.
He is as tall as I.
It is colder today than yesterday.
2、 as+ 形容词/副词原级 +as +省略结构 经常构成固定短语。
You should read as many books as you can.
You should make her as happy as you can.
I will finish my course as soon as possible.
I will help you as soon as I can.
3、 比较状语从句经常与其他的从句混合在一起，并发生位置的变化。
No man thinks more highly than I do of the patriotism, as well as abilities, of the very worthy gentlemen who have just addressed the house.
注意：not so和less后面都是跟形容词或副词原级。
He is not so healthy as his mother.
John is less clever than Peter.
二、比较状语从句常用的表达方式：
1、 The + 形容词/副词比较级（句子），The + 形容词/副词比较级（句子）。
第一种情况：
the+形容词比较级，the+另外一个形容词的比较级
The faster, the better.
The more, the better.
第二种情况：
the+形容词比较级+主语+系动词，the+另外一个形容词的比较级+主语+系动词
The taller you are, the more handsome you look.
The richer you are, the more dangerous you are.
第三种情况：
the+形容词比较级+名词+主语+及物动词，the+另外一个形容词的比较级+名词+主语+及物动词
The more books you read, the more knowledge you get.
第四种情况：
the+方式副词比较级+主语+谓语+（宾语），the+另外一个方式副词比较级+主语+谓语+（宾语）
The more you practice, the better you can speak.
The more carefully you study, the more quickly you make progress.
2、 形容词或副词比较级+ and +同一个形容词或副词比较级。
作表语：
主语+be+形容词的比较级 and+同一个形容词的比较级
She is more and more beautiful.
You will be richer and richer.
作方式状语：
主语+谓语+（宾语）+方式副词比较级+and+同一个方式副词的比较级
You do homework more and more carefully.
He is running faster and faster.
