(1)可以用在肯定句中，表示“像...一樣”，後面的形容詞或者副詞要用原級：
She can run as fast as a deer. 她能跑的像鹿一樣快。
They work as hard as they do. 他們工作像你一樣努力。
(2)也可以用在否定句中，此時和都可以用：
I don't go there as much as I used.我現在到那裏不像過去那麼多了。
I didn't do as(so) well as I should.我做的不如我應做的那麼好。
（3）)用在句中表示程度：
I don't speak half as (so) well as you.我講得不及你一半好。
She can read twice as fast as he does.她的閲讀速度比他快一倍。
注：表示與……一樣的時候，用the same as或者same as ,不可用as same as
