1.as用作副词时主要用来表示比较,意思是“像…一样；如同”。可以单独使用，但更多的是用在as...as结构中，其中第一个as是副词，其后可接形容词或副词,也可接其他成分，as前可有状语。第二个as可以是介词,也可以是连词。as用作副词时还可以指事物以同样的方式发生,意思是“和…一样”。
2.as...as结构多用于肯定式，偶尔也可用于否定式。表示同样意思的否定式多用so...as。as...as结构用于否定句时多用于口语，侧重“像…一样”；so...as结构则多用于书面语，侧重“像…那样”。
3.as...as结构表示的是同级比较，第一个as后的形容词或副词不可用比较级，必须用原级，比较的对象亦须属同类。
4.as...as结构表示数量或程度时，可用于“as much+(不可数名词+) as”或“as many+(可数名词复数+) as”结构。
5.修饰as...as结构的常见词语有nearly,almost,just,exactly,half,quite,表示倍数或次数的形容词，“数词+times”等。这些修饰语都放在as...as结构之前。
6.使用as...as结构时，若第一个as后的名词是单数可数名词并有形容词修饰，则应使用“as+adj.+a/an+n.”结构，即不定冠词应位于形容词和名词之间。第二个as后面的名词或代词的格不同，意思也不同。
7.as...as结构中后一个as用作连词时引导的从句常为省略句，省略从句中的动词可使主句的意义得到加强；反之，重复从句中的动词则可使从句的意义得到强调。
8.使用as...as结构时，在一定的上下文中可以省去其中的一个。
9.as用作副词时不用于比较等级。

as...as
与…一样...to the (specified) degree or extent
She is as pretty as her elder sister. 她和她姐姐一样漂亮。

She is as tall as her mother.她和她母亲一样高。
He runs as fast as Paul.他跑得和保罗一样快。
Ade doesn't play half as well as Cage.艾德演奏的水平不及凯奇的一半。
Smith works as hard as you used to.史密斯和你从前一样工作努力。
Return as much money as you borrowed.借多少就还多少。
You must speak English as much as possible.你必须尽量多说英语。
You've made as many mistakes as I have.你犯的错误和我一样多。
They are having almost as much unemployment as we are.他们的失业者几乎和我们一样多。
The dining room was twice as big as the Tom's.这个餐厅是汤姆的餐厅的两倍大。
This is as difficult a problem as you are likely to meet.像这样的难题,你可能会碰到。
It was as pleasant a day as I have ever spent.那一天我和往常一样过得愉快。
He isn't quite so old as she.他还没有到她那样老的年纪。
He is not as old as she,but older〔younger〕 than she.他并不是和她同样年纪，而是比她老〔年轻〕些。
I'm not as conceited as so many people seem to think.我不像很多人认为的那么自负。
She's smart,but her brother is just as smart.她很聪明，但她兄弟也一样聪明。
The woman married a man poor as herself.这个女人嫁给了一个与她一样穷的男人。

下面各组中句子的意思不同:
They love him as much as she.
他们和她同样爱他。
They love him as much as her.
他们爱他，也同样爱她。
约翰和鲍勃一样有礼貌。
John is as polite as Bob.
(强调约翰有礼貌)
John is as polite as Bob is.
(强调鲍勃有礼貌)

1.她像她母亲那样慈善。
［误］  She was kind as like as her mother.
［正］  She was as kind as her mother.
［正］  She was kind like her mother.
这两台钢琴同样好。
［误］  This piano is equally as good as that one.
［正］  This piano is as good as that one.
［正］  These two pianos are equally good.
［析］  介词like和副词equally同as的词意相同，不能同时出现在一个句子中。
2.你必须尽快离开此地。
［误］  You must get out of this place as immediately as possible.
［正］  You must get out of this place as soon as possible.
［析］  as...as possible结构中的形容词或副词应是可比较的，immediately没有比较级和最高级形式，故不可用于这个结构中。

1.as作“以…的身份,以…资格,作为，以…角色”解时常与动词act,employ,function,serve,speak,work或形容词eminent,distinguished,famous,known,recognized,renowned等连用。
2.as比较常用于as...as和the same...as两个句型。

As a child,he lived in Japan.他小的时候住在日本。
As a schoolboy,he showed every sign of genius.当他还是个小学生的时候,就显示出了天资聪慧。
He worked as a cashier in a bank.他在一家银行干过出纳。
Under the new arrangement I continued as manager.根据新的安排,我继续担任经理职务。
This chair can also function as a bed.这张椅子可兼做床用。
This watch was given me as a birthday present.这只表是作为生日礼物送给我的。
She is known as Mary.她叫玛丽。
France is famous as a wine-producing country.法国以产酒国著称于世。
He does this job as a skilled labour.他做起这个活像个熟手。
He appeared as a man in a trance.他显得神思恍惚。
We chose this one as the most suitable for our purpose.我们之所以选择这一个，因为它最适合于我们的目的。
He wished to join the army,but was rejected as medically unfit.他想要参军，但因体检不合格而未被批准。
It's not nearly as cold as yesterday.今天一点儿也不像昨天那么冷。
The two brothers look and speak the same as each other.这两兄弟长得一模一样，说起话来也一模一样。
Don't regard me as a child.别把我当成小孩看待。
We had better treat it as a joke.我们最好把它当作玩笑。
The dykes were built as a protection against the sea.建筑堤坝是为了防止海水泛滥。
We talked about such subjects as the weather.我们谈论了诸如天气之类的话题。

as, for
这两个词均可作“作为；当作；用作”解,一般情况下可以互换。但as表示资格，而for表示用途。例如：
She was respected as a teacher.
作为一名教师，她受到尊敬。
She won't do for a teacher.
她做教师不行。
另外，在regard,think of,treat等动词之后一般用as,不用for。

as, like
这两个词的区别是：
1.在作“如”“像”解时，as可用作连词，引出方式状语从句；而在正式英语中like不能这样用，只能用作介词。例如：
请尽量按我这样写。
Please try to write as I do.
Please try to write like me.
作为学生，应试时须严格按照上述规定作答，但实际上在非正式的英语里，like用作连词还是很常见的。例如：
I can't sing like I used to.我不能像以前那样唱歌了。
2.as和like都可用作介词，但意义不同。as用于人时强调其身份、职业、地位、角色等,指物时侧重其作用、功能等;like则强调人或事物的外貌特征和性格特征的相像,或行为方式的相同。简言之，as表示一种事实，即“是”;而like则表示一种比喻，即“像”。例如：
She spoke as a lawyer.
她作为律师发言。
She spoke like a lawyer.
她讲话很像是律师。
3.表示动作方式一般用like。例如：
他吃起东西来像头野兽。
［误］ He ate as a beast.
［正］ He ate like a beast.
4.表语词组一般由like引导,而不用as引导。

1.as用作连词时,可以用来表示时间,译为“正当…的时候;随着…;边…边…”,引导时间状语从句。主句可以是主动句,也可以是被动句。当两个主语的动作是同时发生的时候,主句和从句的谓语动词都可以用进行时态或一般式,无论动作长短;当两件事发生的时间间隔很短,甚至没有时间间隔时,主句和从句均用一般过去时;当主句的动作发生在从句的动作发生的过程中的时候,主句和从句可以都用一般过去时,也可以在从句中用进行时态。当表示两个动作的完成时间恰好一致时,as连接的主、从句也都可用过去完成时。
2.as还可表示原因,作“因为,既然”解，引导原因状语从句，表示不说自明的原因或理由，语气较轻，是附带提及，不加强调。as引导的从句可放在主句之前(表示原因不明显),也可放在主句之后(表示原因明显)。
3.as可表示让步,作“尽管”解,引导让步状语从句。当主句的谓语动词是be或其他系词的限定形式时,常用于“名词〔形容词,过去分词〕+as+主语+be〔其他系词〕”的限定形式（名词位于句首时一律不用冠词）;当主句的谓语动词是行为动词时,常用“副词+as+主语+行为动词(+其他附加成分)”的形式。有时也把动词放在从句句首，尤其是有may,might,will,would等情态动词时。注意当主语是名词时常用倒装语序，主语是代词时则不用倒装语序，主语位于谓语之前。
4.as可以引导一个比较关系的状语从句,意思是“像…一样”;为了加强比较的意味,主句中常加副词as（用于肯定句）或so(用于否定句)。此时as可用于“as...as...can〔could〕 be”结构，用来强调形容词的含义，一般可译为“到了…的程度”“极其”。
5.as可以引导方式状语从句,意思是“依照,按照”。
6.as引导比较或方式状语从句时，从句一般采用正常语序，但在正式语体里，也采用倒装语序，但不是强制性的。
7.as还可用于插入语，可置于句首、句中或句末，并常有逗号与句子的其他成分分开。

as against
与…相对照，与…相比之下as compared with
The earth is small as against the sun.跟太阳相比，地球很小。
It increased by one million kilograms as against the figure for last year.产量比去年增加了100万公斤。
He has an income of 15,000 pounds a year, as against the national average of 1300 pounds.他每年收入15,000镑，而全国平均数为1300镑。
He gets weekends off in his new job as against working alternate weekends in his last one.在前一工作岗位，他隔周周末休息，而在新工作岗位他每周周末都休息。

as and when
1.到时候when
We'll decide on our team as and when we qualify for the competition.我们等到有资格参加比赛时再来决定本队参赛人员。
2.可能时when possible
I'll tell you more as and when.有可能的时候我再多跟你说。

as far as
参见far条。

as far as...be concerned
参见concern条。

as follows
参见follow条。

as for
至于,关于speaking of;speaking for;with regard to
〔说明〕 ①as for用于话题转换，即从前面的话题转移到有关的新话题上，并与前面的话题形成对比。
②as for后一般只接名词或动名词，既能用于人，也能用于事物。
③as for一般不用于句首，所引起的短语可用逗号或破折号与句子的其他成分隔开。偶尔用于句首时有不感兴趣或轻蔑之意。
As for her,she has nothing to complain to.至于她，她没有什么可抱怨的。
As for this,I have a few words to say.谈到这一点，我有几句话要说。
As for going back—that is quite out of the question.至于说回去，那完全是不可能的。
As for your hope of winning the first prize, I don't know about that.至于说到你希望获头奖,对此我没有多大把握。
The thief was caught by the police almost immediately.As for the stolen jewels,they were found in a dustbin.小偷几乎当时就被警察抓住。至于偷去的宝石,也在垃圾箱里找到了。
Most people like summer,but as for me,I like winter much better.多数人喜欢夏天，而我却更喜欢冬天。
He doesn't like vegetables much,and as for fruit,he never touches it.他不太喜欢蔬菜，至于水果，他碰都不碰。

as from
自…起from the time started
〔说明〕 as from是英式英语，只用于通告或正式函件。
The contract will be in force as from 1st proximo.本合同将于下月1日生效。
As from tomorrow,no student may enter the principal's office without permission.从明天起，任何学生未经许可不得进入校长办公室。
As from Sunday,May 1st,all fares on the corporation's transport services will be increased by ten pence in the pound.从5月1日即星期日起,本公司运输费将每磅提高10便士。

as good as
参见good条。

as how
1.相当于that,引导名词性从句
He told me as how he was feeling ill.他对我说他感觉不舒服。
He was bragging as how he could run faster than anybody else.他吹牛说他比任何人都跑得快。
2.是否 if;whether
I don't know as how your father will like that.我不知道令尊是否喜欢那样。
It is doubtful as how he is coming.他会不会来还是个问题。

as if〔though〕
好像,似乎,仿佛with the appearance of;apparently
〔说明〕 ①as if〔though〕含有与某些假设的情况作比较的意思，以阐明主语的行为方式或状态。
②as if比as though更常用。
③as if〔though〕引起的从句常可用省略形式，其后常接形容词、介词、动词不定式或分词。
▲引导方式状语从句
〔说明〕 as if〔though〕引导的方式状语从句中的谓语动词多用虚拟语气，指现在的情况时用一般过去时，指过去的情况时用过去完成时。从句中的谓语动词偶尔也可用陈述语气，这时表示的内容可能是真实的，也可能是不真实的。
He likes to talk big as if he was an important person.他老爱说大话，就仿佛他是一位要人似的。
He talks as though he knew all about it.他说话的口气似乎他全都知道了。
He continued with his reading as if nothing important had happened.他若无其事地又继续看他的书。
He walks as if he is drunk.从走路的情况看，他是醉了。
She treats me as though I am/were stranger.她待我形同路人。
The house was lit up as though a big celebration was going on.整个屋子灯火辉煌，犹如在举行盛大庆典。
Eagles were flying up and up as if to ride the white clouds.老鹰越飞越高,好像翱翔在白云之上。
The girl listened as though turned to stone.那姑娘仿佛变成了石头似地倾听着。
▲引导表语从句
〔说明〕 as if〔though〕引导的表语从句中谓语动词可用虚拟语气，也可用陈述语气，完全依说话人对从句内容真实性的判断。在it looks,it seems等结构之后常用陈述语气。
She looks as if she were ill.她看起来像生病一样。
She looks as if she had been ill.她看起来像生过病一样。
He looks as though he would not hurt a fly.他看起来善良得连只苍蝇都不肯伤害。
He felt as if he had lost his power of judgement.他觉得自己仿佛已失去了判断力。
It seems as though it was spring already.现在好像是春天了。
It looks as though it may blow up a gale tonight.看来今晚可能要刮大风。
It sounds as though there is a knock at the door.听起来好像有人在敲门。
▲引导无定形句
〔说明〕 as if〔though〕引导无定形句可以表示惊讶、不信任、愤懑等强烈感情，意思是“好像…似的”“倒是…似的”。
As if I cared!好像我在乎似的〔我才不在乎呢〕！
As if anyone would believe that story.别人才不信那一套呢。

as (it) is
照现状;照原样taking present circumstances into account;as things are
〔说明〕 ①本短语通常置于句末。
②本短语中的it常可省略。
I like the house better as it is.我更喜欢这个屋目前的样子。
Leave it as it is.让它照现在的样子放在那儿〔顺其自然〕。
Take the world as it is.世界就是这个样子，不要奢望什么。
I'm afraid you're simply painting the lily;the picture is good enough as it is.我看你这样做简直是多余，这幅画本来已经够好了。
We bought the clock at an auction as is.那只钟我们从拍卖行买来时就是这个样子。

as it is/was
实际上，事实上as a matter of fact
〔说明〕 本短语暗指事情变得更糟而不是更好。
I thought conditions would get better,but as it is,they are getting worse.我认为情况会转好，但事实上反趋恶化。

as it were
〔说明〕 本短语用作插入语，当觉得自己说的话不够准确或欠妥当时插入其中，以缓和语气。
1.可以说we can say
He is,as it were,a walking dictionary.他可以说是一部活字典。
In many ways children live,as it were,in a different world from adults.从许多方面讲，小孩子可以说是生活在一个跟成人不同的世界里。
He is my best friend,and my second half,as it were.他是我最好的朋友，打个比方说吧，是我的另一半。
2.在某种程度上 to some extent
He became,as it were,a man without a country.他在某种程度上成了一个无国籍的人。
This book gives,as it were,a picture of old China.在某种程度上，这本书提供了一幅旧中国的图景。

as long as
参见long条。

as of
1.自…起from the time started
〔说明〕 as of作此解是美式英语，只用于通告或正式函件。
The law is effective as of May 1.本法律自5月1日起生效。
As of tomorrow,I'll start work half an hour earlier.从明天起我将提前半小时开始工作。
2.直至，在…时up to a specified time;at
As of this writing,no reply has been received.到写这封信时为止，尚未得到答复。
As of now we don't know much about Mars.目前我们对火星还知之甚少。
There has been an increase in the industrial and agricultural output in China as of 1978.根据1978年的材料来看，中国工农业产值已经有所增长。

as often as not
参见often条。

as opposed to
参见oppose条。

as per
按照；根据according to; following
〔说明〕 as per是书面语，只用于正式函件或通告。
The work has been done as per instructions.工作已按指示完成。
The furniture was made as per her order.家具是按她的要求定做的。
We will deliver the goods as per your order.我们将根据你们的订单发货。

as regards
参见regard条。

as...so
像…那样；恰如…一样in a degree equal to that;in a parallel way in which
〔说明〕 ①本结构表示两种情况在趋向或程度上的比例关系，语气强烈，尤用于格言。
②本结构从句总是在主句之前。as前可加just以加强语气。so有时可省略。
③本结构主句的谓语动词如是助动词或be,则有时可以提至主语之前。
As some are very rich,so others are very poor.正像有些人很富一样，另一些人非常贫困。
Just as water is the most important of liquids,so air is the most important of gases.正像水是液体中最重要的一种一样，空气是气体中最重要的一种。
As a tiger stalks his prey,they hunted him.正像老虎阻击猎物一样，他们也抓住了他。
As you sow,so will you reap.种瓜得瓜，种豆得豆。
As I would not be a slave,so I would not be a master.正如我不愿当奴隶一样，我也不愿当奴隶主。

as〔so〕 soon as
参见soon条。

as to
1.至于，谈到as for;with regard to
〔说明〕 as to作此解时用于引入话题，可用于人，也可用于事物。一般位于句首。
As to his mother,I know nothing about her.至于他母亲，我什么情况都不了解。
As to the journey,we must decide about that later.至于旅行，我们必须以后再定。
As to what's ahead,you can be anything you choose.至于将来，你想干什么都会成功。
As to your second question, I am afraid I can give you no information at the moment,as the matter is still under consideration.至于你的第二个问题，目前恐怕无可奉告，因为这事尚在考虑中。
As to your wish to have an extra secretary, let's leave it open until the next fiscal year.你希望增补一名秘书的事，到下一财政年度再定。
2.关于about;regarding
〔说明〕 ①as to作此解时通常与名词agreement,complaint,dissatisfaction,doubt,idea,question和动词argue,decide,defer等连用。
②as to作此解时还可接“疑问词+动词不定式”结构，也可接由疑问词引导的从句。
③as to作此解时一般位于句中。
He has no complaint as to his salary.对薪酬他没意见。
A lawyer should advise his clients as to their legal rights as a passenger.律师应对其委托人争取旅客合法权益出主意。
Nobody could decide as to what to do.没人能决定做什么。
He was at a loss as to how to meet the situation.他手足无措,不知该怎样应付这一局面。
He inquired as to whether her old grandmother was still alive.他询问她老祖母是否还在世。
A question arose as to who was the legal heir.出现了谁是合法继承人的有争议的问题。
A near-total news blockout kept the outside world guessing as to what was really happening at the summit.由于对会议实行了全面新闻封锁，外界人士对首脑会议只能进行猜测。
3.成比例in proportion
〔说明〕 as to作此解时一般位于句中。
The value of a book is as to its content,and not as to its size.一本书的价值同它内容的好坏成比例，而与版本大小无关。
4.按照according to;by
They sorted eggs as to size and colour.他们按照大小和颜色挑选鸡蛋。

as usual
像平常一样in the usual way
〔说明〕 本结构中的usual可根据情况用always,ever等词替换。
He was late,as usual.他像平常一样迟到了。
As usual,Tommy forgot to make his bed before he went out to play.如往常一样，汤米又忘记在出去玩之前把床铺整理好。
Mrs. Carey as usual wet to the door to see him off.凯丽太太像往常一样走到门口向他告别。
As ever,the train got in just too late for me to catch the early bus.像往常一样，火车到得太晚，我没能赶上早班车。

as well
参见well条。

as well as
参见well条。

as yet
参见yet条。

even as
参见even条。

in so far as
参见far条。

just as well
参见well条。

may as well
参见well条。

much as
参见much条。

regarded as
参见regard条。

so as to
参见so条。

so...as to
参见so条。

引导时间状语从句
I was coming in as he was going out.我进来的时候,他正出去。
My pen trembles as I write it.我一边写,笔一边颤抖。
Helen heard the story as she washed.海伦洗衣服的时候听了这个故事。
As I left the house I remembered the key.当我离开房间的时候,我想起了钥匙。
As I was coming here,I met your brother.我来这儿的时候遇见了你哥哥。
The boy's eyes had slowly moved to him as he had spoken.他说完时,这孩子的眼光已慢慢地移到他身上。
引导原因状语从句
As rain has fallen,the air is cooler.由于下了雨，空气比较凉爽。
As he has not ready in time,we went without him.由于他未能及时准备好，我们没有等他就走了。
As this question is of great interest,we will discuss it once again.因为这个问题很有意义,所以我们决定再讨论一次。
I can't come tonight,as I'm going to a concert.今晚我不能来,因为我要去听音乐会。
I am going to bed,as I am very tired.我疲倦得很，要去睡了。
引导让步状语从句
Child as is Paul,he knows enough to tell good from bad.保尔虽是个孩子，却已懂得区分好坏。
Coward as he was,however,Flashman couldn't swallow such an insult as this.弗拉西曼虽然是个胆小鬼,也不能忍受这种屈辱。
Simple as was the idea,the then scientific world would have none of it.虽然这概念很简单，但当时的科学界却不知道这一点。
Intelligent as you are,I suspect you will fail.尽管你聪明,我还是猜想你会失败。
Surrounded as we were by the enemy,we managed to march forward.尽管我们被敌人包围了,我们还是决心向前进。
Quickly as it spread and threatening as it appeared to be,the result was doomed from the start.尽管起义发展很快,声势浩大,但它从开始时起就注定了要失败。
He was unable to make much progress,hard as he tried.尽管他努力了,但他没能取得多少进步。
Try as I might,I couldn't lift the stone.无论我怎么努力也搬不动这块石头。
引导比较状语从句
Run as fast as you can.你能跑多快就跑多快。
Poets are not so scrupulous as you are.诗人并不像你那样顾虑多。
I'm as happy as happy can be.我快乐极了。
引导方式状语从句
When in Rome,do as the Romans do.入乡随俗。
State the fact as it is.照实讲来。
Balloons float in the air as boats float on water.气球飘在空中如同船浮在水上一样。
Things were almost as they had been before.事情还像以前一样。
She looks forward,as does her secretary,to the completion of the building.她像她的秘书那样盼望工程竣工。
用于插入语
As I said in my last letter,I am taking the exam in July.我上次信里已经说过，我七月份要考试。
All the while,as I say,I was still running.我说,我一直是在跑着。

as a matter of fact, as good as, as it is
这三个短语都有“实际上，事实上”的意思，其区别是：as a matter of fact含有对比之意,说的是与已知的或已说过的内容不同的内容；as good as没有对比的意味，意思是“实质上差不多等于”；as it is则用于指出即将说的是一个事实。例如：
Mike said he didn't tell a lie.As a matter of fact, he did.迈克说他从没有说过谎。事实上,他说过。
He as good as refused.他实际上等于拒绝了。
We had hoped to finish today,but as it is we probably won't finish until tomorrow.我们原本希望今天能做完它，但实际情况是我们或许要等到明天才能做完。

as, because, for, since
这四个词都可以作连词引导一个表示原因的状语从句。其区别是:
1.because是从属连词,引导的原因状语从句指的是自然、直接的原因,主句表示必然的因果关系,而原因构成句子的主要部分,是句子的重点。另外,because引导的从句多放在句末,但有时也可放在句首,这种情况往往是为了强调。
2.如果原因很明显或已为人们所知,或不如句子的其余部分重要,就用as或since,since比as更正式一些,这两个词都为从属连词,常译为“由于,既然”,语气比because轻。as和since引导的句子多放在整个句子的开头,偶尔它们引导的(特别是since引导的)句子也可以放在后面。since作为理由有“不好”或“勉强”的含意;而as只将既成事实作为理由,并不含有“不好”或“勉强”的意味。
3.for是并列连词,引导的是并列从句,表示原因的语气很弱,一般是对结果作推断性的补充说明或解释,不表示直接原因。for较正式,很少用于口语,一般用于书面语,前面一般多用逗号。

as it is/was, as it were
as it is/was是个短语，意思是“实际上”“事实上”“照目前情况来看”，用于把可能的情景与实际发生的情况进行对比；而as it were的意思则是“可以说是”“似乎是”“仿佛”，表示所说的话听起来不那么肯定。

as, though
这两个词用作从属连词引导让步状语从句时，都可采用倒装语序。其区别在于：as采用这种倒装语序是强制性的，而though则是非强制性的。此外，as引导的这种倒装语序还可表示原因，而though则无此功能。

as, when, while
这三个词都可作连词引导一个表示时间的状语从句。as引导的从句作“当…时”或“和…同时”解,从句中的动作与主句中的动作同时发生或同时进行,一般持续时间不长;when引导的从句作“当…时”或“每逢…”解,从句中的动作既可以和主句中的动作同时发生,也可以在主句的动作之前或之后发生;while引导的从句作“当…时”或“在…期间”解,它强调从句中的动作与主句中的动作同时发生,但持续时间一般较长或主句的动作在从句的动作过程中发生。while与as和when的最大区别在于有时含有“趁着…情况的存在赶紧做某事,否则来不及了”的意味。

as well, also, besides, either, moreover, too
参见too条。
下面两个句子的意思不同:
We have a third as many students in our
class as we had last term.
我们班的学生是上学期的三分之一。
We have a third as many students again
in our class as we had last term.
我们班的学生比上学期多了三分之一。

［词源］＜中古英语as(像,同样)