as...as 的用法
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：
(1)This story is as funny as that one.
这www.58yuanyou.com个故事和那个一样滑稽可笑。
(2)His bike rides as well as hers.
他的自行车和她的一样好骑。
其否定式为 not as/so +adj./ adv. +as。例如：
This book is not so/as necessary as they say.
这本书不想他们说的那么必不可少。
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 car is twice as big as mine.
你的车是我的两倍大。
几个关于 as...as 的常见句型：
(1)as...as possible
They ran away as quickly as they could.
请尽快回答我的问题。
(2)as...as usual/before
He looks as handsome as before.
他看起来和以前一样英俊。
(3)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。
(4) as far as
We walked as far as 2 kilometres yesterday.
昨天，我们三步两公里远。
(5) as well as
He paints as well as his father does.
他画的画和他父亲一样好。
一些带有 as...as 结构的常见短语归纳：
as busy as a bee 像蜜蜂一样忙碌
as easy as ABC 像 ABC 一样容易
as deep as a well 像井一样深
as light as a feather 像羽毛一样轻
as soft as butter 像黄油一样软
as rich as a Jew 像犹太人一样富裕
常见的还有：
as green as grass 碧绿如青草
as big as an elephant 大如象
as small as a pea 小似豆
as red as an apple 红如苹果
as happy as a bird 开心得像只小鸟
as 原由网white as snow 雪白
as black as a mouse 黑似老鼠
as quiet as a sheep 腼腆如小羊
一、“as(否定句中可用 so)＋adj．／adv．＋as…”，其基本意思为“……和……一样”。但在实际应用中，此结构在不同的语境中含义差异较大。
1、表示不同人或物同一性质的比较，意为“……和……一样……"。
The wall is as white as snow．
这墙面雪白雪白的。
Mike is as intellent as Ben．
迈克与本一样机智。
2、表示同一个人或物不同性质的比较，意为“既……又……”
Karen talks as happily as she dances．
凯润愉快交谈，尽情跳舞。
Frank is not so wise as he is witty．
弗兰克为人风趣，但欠明智。
3、用于表示两个人或物不同性质的比较，表示程度相同或相当，意为“……而……”。
He was as handsome as his wife was beautiful．
他长得非常英俊，他的妻子也长得非常漂亮。
He was as experienced as his brother was green．
他经验丰富，而他兄弟却涉世未深。
二、as…as 结构的另一种形式是“as much／many＋名词＋as＋从句”。
Martin has painted as many pictures as his hather．
马丁已经画了和他爸爸一样多的画。
It is as much your fault as your his．
这既是你的过错，也是他的过错。
Henry is as much a hero as John．
亨利跟约翰一样是个英雄。
三、若有修饰成分，如 twice，three times，half，a quaer 等，必须置于第一个 as 之前。
You are not half as wise as you think．
你可不像自己想象的那么智慧。
She will never go out with a man who is twice as old as she．
她永远不会和一个比她大一倍的人出去散步。
He's made just as many mistakes as I have．
他和我犯的错误一样多。
We’ve produced twice as much cotton this year as we did last year.
我们今年的棉花产量是去年的两倍。
四、as…as 结构的另一变体形式是“as＋形容词原级＋名词词组＋as”
I don't want as expensive a car as this.
＝I don't want a car as expensive as this．
我不要这么贵的汽车。
Tony is as clever a boy as his brother．
托尼是一个和他兄弟一样聪明的男孩。
五、当 as…as 与表示重量、数量、时间、距离、价格等的计量名词连用时。往往并不表示比较。而是构成一个形容词组，意为“重达……，多达……，高达……”等。
The river is as deep aslO meters．
这条河深达 10 米。
Frosts often occur as late as May．
往往到 5 月份还有霜。
六、“as+原级+asany(或 ever)”、“as+原级+as…canbe”、“nothing(或 no)＋so＋原级＋as…”等结构表达的是最高级意义。即在某种程度上或某方面达到极限或最大限度。
He is as great a mathematician as any．
他是一位非常杰出的数学家。
He is as happy as happy can be．
他幸福无比。
No one is so deaf as those who won’t listen．
最聋者莫过于不听劝说的人。
七、as…as…不表示比较的几个常见句型。
1．as…as possible／sb can 尽 可 能 的 ……
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……
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
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。
一、as 作连词的用法
1. as...as 的用法
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：
(1) This film is as interesting as that one.
这部电影和那部电影一样有趣。
(2) Your pen 原由网writes as smoothly as mine.
你的钢笔书写起来和我的一样流畅。
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。
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。几个关于 as...as 的常见句型：
(1) as...as possib//www.58yuanyou.comle
Please answer my question as soon as possible.
请尽快回答我的问题。
(2) as...as usual/before
She looks as pretty as before.
她看起来和以前一样漂亮。
(3)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。
(4) as far as
He walked as far as the railway station yesterday evening.
昨天傍晚，他一直散步到火车站。
(5) as well as
She cooks as well as her mother does.
她烧菜烧得跟她母亲一样好。一些带有 as...as 结构的常见短语归纳：
as busy as a bee 像蜜蜂一样忙碌
as easy as ABC 像 ABC 一样容易
as deep as a well 像井一样深
as light as a feather 像羽毛一样轻
as soft as butter 像黄油一样软
as rich as a Jew 像犹太人一样富裕
2. as 用作连词引导时间状语从句
as 与 when，while 都是引导时间状语从句的从属连词，含义都是"当…… 的时候"。但它们有区别：
用 when 时，从句的动作可以与主句的动作同时发生， 也可以先于主句的动作发生；
用 while 时，从句原由网的动作为一过程，主句动作与从句动作同时进行或在从句动作过程中发生；
用 as 时，主句和从句的动作同时发生，具有延续的含义。例如：
(1) It was snowing when he arrived at the construction site.
他到达工地时，天正在下雪。
(2) He was watching TV while his mother was cooking.
他母亲做饭时他在看电视。
(3) You will grow wiser as you grow older.
你会随着年龄的增长而越来越聪明。
3. as 用作连词引导原因状语从句
as，because，since 都可以表示因果关系，连接原因状语从句，含义是" 因为，由于"，但它们有区别：because 表示的语气最强；as 一般放在句首，语气较弱，较口语化；since 常常用在书面语中，表示多为对方已知的、或稍加分析便可得知的原因，有时可译作"既然"。例如：
(1) He will succeed because he is in earnest.
他一定会成功，因为他很认真。
(2) Since you are so sure of it he”ll believe you.
既然你对此如此有把握，他会相信你的。
(3) As rain has fallen, the air is cooler.
因为下过雨，空气比较清爽。
4. as 作连词引导让步状语从句
as 与 although (或 though)，however (或 no matter how)等都可以引导让步状语从句，但有所不同：
although 语气稍正式些，主句中不能再用 but，但可以用 yet；
as 所表示的语气较强，引导的让步状语从句用倒装语序；
however 引导让步状语从句时， 它的后面可跟形容词或副词，也要用倒装语序。例如：
(1)Although he is rather old, he still takes a long walk every day.
尽管他已经是上了春秋的人，他依然每天散步很长时间。
(2) Strange as it may seem, nobody was injured in the accident.
这个事故虽然看上去怪怪的，可是却没有人受伤。
(3) However hard I have tried, I still can't achieve my dream.
无论我如何尝试，都无法实现我的梦想。
二、as 作关系代词的用法
关系代词 as 引导定语从句时，其用法要比 that 和 which 复杂。
1. as 引导定语从句的搭配
①用于 the same...as 结构中
This is the same book as you bought.
这本书和你买的一样。
②用于 such...as 结构中
I don't like such books as he suggests.
我不喜欢他建议的那些书。
③用于"so +adj. + a/an + n. (单数) + as "结构中
I am not so active as I was.
我不像以前那么精力充沛了。
2. as 单独引导定语从句
as 单独引导定语从句时，先行词可以是一个词，也可以是一个句子或短语。例如：
(1) He is late again, as is often the case.
他又迟到了，这是家常便饭。(as指代前面整句话)
(2) To shut your eyes to facts, as many of you do, is foolish.
对事实视而不见--你们好多人都是如此的愚蠢。(as指代前面的不定时短语)
三、as 当介词用
as 作介词，意思是"作为"，"以……身份"。例如：
He works as an English in our school.
他以英语老师的身份在我们学校工作。
四、as 作副词的用法
意思接近to the same degree or amount; equally "相同地"，"同样地"。例如：
We don't have as much as money.
我们没有同样多的钱。
