1、此句型用于平级比较，第一个as是副词，第二个as是连词，中间加的是形容词或副词的比较级。例如：

This bridge is as long as that one.

He runs as fast as Jack.

2、中间如果加名词的话分为两种情况。

（1）加可数名词单数，注意要先加形容词再加不定冠词。如

He is as good a boy as Tom.

（2）加可数名词复数，不可数名词只能用many和much修饰，如

I have as many books as you have.

I have as much money as you have.