as...as表示像...一樣，（強調(diào)數(shù)量）多達，只有。通常中間只能用形容詞或副詞的原級，不能用比較級或最高級。若第二個as之后使用獨立的人稱代詞，一般用主格(較正式)或賓格(非正式)均可。

1.若涉及數(shù)量或程度，可用“as much+不可數(shù)名詞+as”和“as many+可數(shù)名詞復數(shù)+as”。如：

He doesn’t pay as much tax as we do / as us. 他沒我們交的稅款多。

There are not as many restaurants as there were. 現(xiàn)在餐館沒有過去多了。

2.“as+形容詞或副詞原級+as...”意為“和...一樣”，表示同級的比較，第一個as為副詞，第二個as為連詞。

（1）as...as結(jié)構(gòu)用于表示不同人或物同一性質(zhì)的比較，意為...和...一樣

The tree is as tall as the building.這棵樹和那棟樓一樣高。

（2）as...as結(jié)構(gòu)用于表示同一個人或物不同性質(zhì)的比較，意為既...又...

This swimming pool is as wide as it is long.

這個游泳池寬度和長度相等。

（3）as...as結(jié)構(gòu)用于表示兩個人或物不同性質(zhì)的比較，表示程度相同或相當，意為...而...，在否定句結(jié)構(gòu)是so/as...as...

He cannot run so/as fast as you.他沒你跑得快。

He was as handsome as his wife was beautiful.

他長得很英俊，他的妻子也長得非常漂亮。

3.as...as的常見句型

（1）as...as possible／sb can盡可能的……

Please answer my question as soon as possible．

請盡快回答我的問題。

The detective is searching the man as carefully as he can．

那個偵探正在盡可能仔細地搜查那個男子的身體。

（2）as...as usual／before像以前一樣……

She looks as pretty as before．

她看起來和以前一樣漂亮

Though they failed，they still worked as hard as usual．

盡管他們失敗了，但他們?nèi)韵褚郧耙粯优ぷ鳌?/p>

（3）as long as只要，引導條件狀語從句

I will stay with you as long as there is a room free．

要是你有一間空余的房子，我就住在你這里。

You may borrow this book as long as you promise to give it back

只要你答應歸還，你就可以把這書借走。