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。
as...as的用法
1、接形容词或副词的原级，在否定句中，第一个 as 也可换成 so。
例句：He doesn't study as (so) hard as his brother. 他学习不如他弟弟努力。
2、表示涉及数量或程度，可用“as much+不可数名词+as”和“as many+可数名词复数+as”。
例句：He doesn’t pay as much tax as we do / as us. 他没我们交的税款多。
3、可用(not) nearly, almost, just, nothing like, exactly, not quite, half, one-ten, twice, three times, 30 per cent等修饰，并且这些修饰语必须置于第一个as之前，而不能置于其后。
例句：This room is twice as large as that one. 这个房间是那个房间的两个大。
as…as…的常见句型
1、as…as possible/sb can尽可能的……
例句：
Please answer my question as soon as possible.
请尽快回答我的问题。
The detective is searching the man as carefully as he can.
那个侦探正在尽可能仔细地搜查那个男子的身体。
2、as…as usual/before像以前一样……
例句：
She looks as pretty as before.
她看起来和以前一样漂亮
Though they failed，they still worked as hard as usual.
尽管他们失败了，但他们仍像以前一样努力工作。
3、as long as只要，引导条件状语从句
例句：
I will stay with you as long as there is a room flree.
要是你有一间空余的房子，我就住在你这里。
You may borrow this book as long as you promise to give itback.
只要你答应归还，你就可以把这书借走。
小编推荐
1.mean to do和doing的区别 mean有哪些用法
下载文档