一、基本用法

　　as ... as

　　用于比較句型,中間插入的是形容詞或副詞的原級(jí)。意思是"達(dá)到與什么相同的程度"。如：He is as strong as a horse. 他力大如牛。

　　二、習(xí)慣用法

　　1. as soon as

　　意思是"一......就......",引導(dǎo)一個(gè)時(shí)間狀語(yǔ)從句。如：I'll call you as soon as I finish my homework. 我一完成我的作業(yè),就給你打電話。

　　2. as long as

　　意思是"長(zhǎng)達(dá)......之久;只要......"。如：She has searched the information about dinosaurs on the Internet as long as three hours. 她在因特網(wǎng)上搜索有關(guān)恐龍的信息已經(jīng)長(zhǎng)達(dá)三個(gè)小時(shí)。

　　3. as much as

　　意思是"高達(dá)......;與......一樣多"。是用來(lái)表達(dá)極其多的語(yǔ)氣。如：Some of the stones weigh as much as fifteen tons.有些石頭重達(dá)15噸。

　　★as...as用法：

　　as...as意為"和……一樣"，表示同級(jí)的比較。使用時(shí)要注意第一個(gè)as為副詞，第二個(gè)as為連詞。其基本結(jié)構(gòu)為：as+ adj./ adv. +as。

　　例如：

　　(1)This film is as interesting as that one.這部電影和那部電影一樣有趣。

　　其否定式為not as/so +adj./ adv. +as。例如：

　　This dictionary is not as/so useful as you think.這本字典不如你想象的那樣有用。

　　若有修飾成分，如twice, three times, half, a quarter等，則須置于第一個(gè)as之前。

　　例如：

　　Your bag is twice as expensive as mine.你的袋子比我的貴一倍。

　　幾個(gè)關(guān)于as...as的常見(jiàn)句型：

　　(1)as...as possible

　　Please answer my question as soon as possible.請(qǐng)盡快回答我的問(wèn)題。

　　(2)as...as usual/before

　　She looks as pretty as before.她看起來(lái)和以前一樣漂亮。

　　(3)as long as... (引導(dǎo)條件狀語(yǔ)從句)

　　It took us as long as three years to carry out the plan.我們花了長(zhǎng)達(dá)三年的時(shí)間才完成這項(xiàng)計(jì)劃。

　　(4)as far as

　　He walked as far as the railway station yesterday evening.昨天傍晚，他一直散步到火車(chē)站。

　　(5)as well as

　　She cooks as well as her mother does.她燒菜燒得跟她母親一樣好。

　　★as...as的結(jié)構(gòu)：

　　as + 形容詞或副詞原級(jí) + as

　　1)在否定句或疑問(wèn)句中可用so… as。

　　He cannot run so/as fast as you.

　　2)當(dāng)as… as 中間有名詞時(shí)采用以下格式。

　　as +形容詞+ a +單數(shù)名詞

　　as + many/much +名詞

　　This is as good an example as the other is.

　　I can carry as much paper as you can..

　　3)用表示倍數(shù)的詞或其他程度副詞做修飾語(yǔ)時(shí)，放在as的前面。

　　This room is twice as big as that one.

　　Your room is the same size as mine.

　　4) 倍數(shù)+ as + adj. + as　<=> 倍數(shù)+ then + of

　　This bridge is three times as long as that one.

　　This bridge is three times the length of that one.

　　Your room is twice as large as mine.

　　Your room is twice the size of mine.