1、as...as意为"和……一样"，表示同级的比较。
使用时要注意第一个as为副词，第二个as为连词。其基本结构为：as+ adj./ adv. +as。例如：
This film is as interesting as that one.
这部电影和那部电影一样有趣。
2、其否定式为not as/so +adj./ adv. +as。
例如：
This dictionary is not as/so useful as you think.
这本字典不如你想象的那样有用。
3、若有修饰成分，如twice, three times, half, a quarter等，则须置于第一个as之前。例如：
Your bag is twice as expensive as mine.
你的袋子比我的贵一倍。
4、几个关于as...as的常见句型：
a、as...as possible
Please answer my question as soon as possible.请尽快回答我的问题。
b、as...as usual/before
She looks as pretty as before.她看起来和以前一样漂亮。
c、as long as... (引导条件状语从句)
It took us as long as three years to carry out the plan.我们花了长达三年的时间才完成这项计划。
d、as far as
He walked as far as the railway station yesterday evening.昨天傍晚，他一直散步到火车站。
e、as well as
She cooks as well as her mother does.她烧菜烧得跟她母亲一样好。
5、一些带有as...as结构的常见短语归纳：
a、as busy as a bee像蜜蜂一样忙碌
b、as easy as ABC像ABC一样容易
c、as deep as a well像井一样深
d、as light as a feather像羽毛一样轻
e、as soft as butter像黄油一样软
扩展资料
AS：
副词adv.
1、跟...一样地,同样地 例如:I'm as tall as him 我和他一样高。
2、 如同;例如 例如:There are lots of famous buildings as the Eiffel Tower and the Arch of
Triumph. 这里有许多著名建筑如埃菲尔铁塔和凯旋门。
介词prep.
1、作为,以...的身份 例如:He works as a tour guide. 他作为导游工作。
2、 当作 例如:She is a famous person as a actress. 作为一个女演员,她很出名
3、 像;如同 例如:The old woman was dressed as a young lady. 这位老妇人打扮得像一位
年轻人。
连接词conj.
1、像...一样；依照；像 例如:You ought to do as Paul tells you. 你应按照保罗吩咐的做。
2、 当...时 例如:As she was leaving the room she remembered that book. 她离开房间时想起了
那本书。
3、随着 例如:As the sun rose the fog dispersed. 太阳一出来,雾随之消失。
4、因为 例如:We didn't know what to do as we were just visiting there. 我们不知道该
怎么办，因为当时我们仅仅在那里作访问。
5、 虽然 例如:Tired as he was, he stayed up late. 他虽然疲倦，可仍然很晚才睡。
6、尽管 例如：Try as she might,Sue couldn't get the door open.尽管想尽一切办法，苏还是不能打开那
扇门
参考资料：百度百科：AS