as+形容词/副词+as或as+形容词+名词+as。固定用法“as...as possible”意为“尽可能地...”,例如“as quicky as possible尽可能地快”，“as much as possible 尽可能地多”，“as carefully as possible 尽可能地小心”等等。

1.as...as结构的基本意思是“与……一样”，其中接形容词或副词的原级，在否定句中，第一个as也可换成so。如：

He doesn't study as/so hard as his brother. 他学习不如他弟弟努力。

2.若涉及数量或程度，可用“as much+不可数名词+as”和“as many+可数名词复数+as”。如：

He doesn’t pay as much tax as we do / as us.他没我们交的税款多。

There are not as many restaurants as there were.现在餐馆没有过去多了。

3.as...as接形容词时，有时该形容词还可修饰另一名词，但这个名词应带有不定冠词（注意词序）。如：

I have as good a voice as you.我的声音和你一样好。