as是英語(yǔ)考試中用得比較多的一個(gè)詞，也是很多學(xué)生反映較難掌握的一個(gè)詞。as的詞性較多，用法也較復(fù)雜，因此掌握該詞會(huì)對(duì)英語(yǔ)學(xué)習(xí)很有幫助。下面是小編整理的一些關(guān)于as用法小結(jié)， 希望讓大家更好地認(rèn)識(shí)as這個(gè)單詞，提高英語(yǔ)水平。

　　as用法小結(jié)

　　一、as作為從屬連詞，可以引導(dǎo)下列從句：

　　1、as引導(dǎo)時(shí)間狀語(yǔ)從句，意為“正當(dāng)……的時(shí)候”、“一面……一面……”、“隨著……”，從句可放主句之前或主句之后。

　　As I was coming here, I met your brother.

　　As he walked on, he felt himself getting more and more tired.

　　【知識(shí)拓展】：as與when, while都是引導(dǎo)時(shí)間狀語(yǔ)從句的從屬連詞，含義都是"當(dāng)……的時(shí)候"。但它們有區(qū)別：用when時(shí)，從句的動(dòng)作可以與主句的動(dòng)作同時(shí)發(fā)生，也可以先于主句的動(dòng)作發(fā)生;用while時(shí)，從句的動(dòng)作為一過程，主句動(dòng)作與從句動(dòng)作同時(shí)進(jìn)行或在從句動(dòng)作過程中發(fā)生;用as時(shí)，主句和從句的動(dòng)作同時(shí)發(fā)生，具有延續(xù)的含義。例如：

　　It was snowing when he arrived at the construction site.他到達(dá)工地時(shí)，天正在下雪。

　　He was watching TV while his mother was cooking.他母親做飯時(shí)他在看電視。

　　You will grow wiser as you grow older.你會(huì)隨著年齡的增長(zhǎng)而越來(lái)越聰明。

　　2、as引導(dǎo)原因狀語(yǔ)從句，意為“由于”大多位于主句之前，偶爾在前或后。

　　As this question is of great importance, we will discuss it once again.

　　Water, as it occurs in nature, is never very pure.

　　We couldn‘t send the children to school as life was very hard in those days.

　　【知識(shí)拓展】：as, because, since都可以表示因果關(guān)系，連接原因狀語(yǔ)從句，含義是“因?yàn)?，由?rdquo;，但它們有區(qū)別：because表示的語(yǔ)氣最強(qiáng);as一般放在句首，語(yǔ)氣較弱，較口語(yǔ)化;since常常用在書面語(yǔ)中，表示多為對(duì)方已知的、或稍加分析便可得知的原因，有時(shí)可譯作“既然”。例如：

　　He will succeed because he is in earnest.他一定會(huì)成功，因?yàn)樗苷J(rèn)真。

　　Since you are so sure of it he’ll believe you.既然你對(duì)此如此有把握，他會(huì)相信你的。

　　As rain has fallen, the air is cooler.因?yàn)橄逻^雨，空氣比較清爽。

　　3、方式狀語(yǔ)從句，意為“如同”、“按照……的方式、樣子、辦法”。As從句總跟在主句之后。

　　You must try to hold the tool as I do. 象我那樣拿住工具。

　　Leave things as they are. 讓那些東西保持原樣。

　　3、as引導(dǎo)讓步狀語(yǔ)從句，意為“雖然”，多在主句之前，且多用倒裝。(應(yīng)將從句主要成分的形容詞、副詞、原形動(dòng)詞、不加冠詞的單數(shù)名詞置于as 前面)

　　Difficult as it is, we should not give it up.

　　Child as he is, he knows something about electricity.

　　【知識(shí)拓展】：as與although (或though)，however (或no matter how)等都可以引導(dǎo)讓步狀語(yǔ)從句，含義是“雖然，盡管”，但它們有區(qū)別：although語(yǔ)氣稍正式些，可放在句首，也可放在句中，主句中不能再用but，但可以用yet;as所表示的語(yǔ)氣較強(qiáng)，引導(dǎo)的讓步狀語(yǔ)從句用倒裝語(yǔ)序;however引導(dǎo)讓步狀語(yǔ)從句時(shí)，它的后面可跟形容詞或副詞，也要用倒裝語(yǔ)序。例如：

　　Although he is quite old, he still jogs every day.他雖然年紀(jì)相當(dāng)大，仍然每天慢跑。

　　Strange as it may seem, nobody was injured in the accident.

　　這次意外雖然顯得令人不可思議，卻沒有人受傷。

　　However hard he may try, he will not attain his goal.無(wú)論他怎樣努力也達(dá)不到目標(biāo)。

　　4、as引導(dǎo)比較狀語(yǔ)從句，意為“和……一樣/不一樣”。 表示同級(jí)的比較。使用時(shí)要注意第一個(gè)as為副詞(意為“那么”“如此”)，第二個(gè)as為連詞(引導(dǎo)的比較狀語(yǔ)從句常常用省略)。其基本結(jié)構(gòu)為：as+ adj./ adv. +as。例如：The line AB is as long as the line CD (is).

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

　　Your pen writes as smoothly as mine.你的鋼筆書寫起來(lái)和我的一樣流暢。

　　注意1：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。

　　注意2：“as…as…”結(jié)構(gòu)前加上表示程度或倍數(shù)的詞語(yǔ)作為修飾成分，如just, nearly, almost, 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。

　　This is just as important an experiment as that(is).

　　There are now three times as many schools in this city as(there were )ten years ago.

　　【知識(shí)拓展1】：幾個(gè)關(guān)于as...as的常見句型：

　　(1)as...as possible

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

　　(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。

　　【知識(shí)拓展2】：一些帶有as...as結(jié)構(gòu)的常見短語(yǔ)歸納：

　　as busy as a bee像蜜蜂一樣忙碌 　　 as easy as ABC像ABC一樣容易

　　as deep as a well像井一樣深 　　 as light as a feather像羽毛一樣輕

　　as soft as butter像黃油一樣軟 　　 as rich as a Jew像猶太人一樣富裕

　　as strong as a horse健壯如牛 as poor as a church mouse一貧如洗

　　as cool as a cucumber十分冷靜;鎮(zhèn)定自若

　　二、as作為關(guān)系代詞，可以引導(dǎo)定語(yǔ)從句，既可以單獨(dú)使用，也可以與其他詞連用，其用法要比that和which更為復(fù)雜，而且as在定語(yǔ)從句中可以充當(dāng)主語(yǔ)、賓語(yǔ)、介詞賓語(yǔ)、表語(yǔ)，可以指人也可指物。要注意引導(dǎo)定語(yǔ)從句時(shí)。

　　1、引導(dǎo)限制性定從句。

　?、儆糜趖he same...as結(jié)構(gòu)中。

　　This is the same book as I read last week.這本書和我上周讀的那本是一樣的。

　　He isn’t the same person as he used to be.

　?、谟糜趕uch...as結(jié)構(gòu)中。

　　I have never heard such story as he is telling.

　　I don’t like such books as he recommends. 我不喜歡他推薦的那些書。

　　③用于"as/so +adj. + a/an + n. (單數(shù)) + as "結(jié)構(gòu)中

　　I am not so strong a man as I was.我已經(jīng)沒有從前那么強(qiáng)壯了。

　　2、引導(dǎo)非限制性定從句，修飾整個(gè)主句或主句的一部分，可在句首、句中、句末。當(dāng) as 在從句中做主語(yǔ)時(shí)，從句的謂語(yǔ)動(dòng)詞常是被動(dòng)語(yǔ)態(tài)或系表結(jié)構(gòu)。在從句中做賓語(yǔ)時(shí)，從句的謂語(yǔ)動(dòng)詞常是情態(tài)動(dòng)詞 + 動(dòng)詞原形。

　　As is often the case, we have overfull filled the production plan.

　　This machine, as might be expected, has stopped operating.

　　He came very early this morning, as (was) usual.

　　She is late, as is often the case.她遲到了，這是經(jīng)常的事。(先行詞是整個(gè)主句)

　　To shut your eyes to facts, as many of you do, is foolish.

　　對(duì)事實(shí)視而不見--你們好多人都是如此的愚蠢。(先行詞是不定式短語(yǔ))

　　此外還有: as has been said before/ as may be imagined / as is well known/ as we all can see/ as often happens/ as has already been pointed out等等。

　　三、as作為介詞的用法：

　　1. 表示“好像”。如:He dressed as a policeman.

　　2. 表示“作為”，“當(dāng)作”。如：I found a job as a guide.

　　3. 表示某人是什么某身份時(shí)。如：As a child , she was sent to abroad.

　　He came to China as a tourist five years ago.他五年前以游客的身份來(lái)過中國(guó)。

　　4. as引導(dǎo)的介詞短語(yǔ)大多用作狀語(yǔ),as譯為"作為";少數(shù)情況可引起賓語(yǔ)補(bǔ)足語(yǔ)。如:

　　As a Party member, I'll take the lead in everything. (狀語(yǔ))

　　She works as a model. (狀語(yǔ))

　　She has me as one of her best friends.(引起賓語(yǔ)補(bǔ)足語(yǔ))

　　四、as作為副詞的用法：

　　1、意思為“相同地”，“ 同樣地”=(to the same degree or amount; equally)

　　例如：They don’t have as many airplanes.他們沒有同樣多的飛機(jī)。

　　This dress is twice as expensive as that one.

　　2、意思為“像，如”等。如：As before, he remained unmoved.

　　總之，通過以上的分析，我們對(duì)as的詞性和用法有了比較全面的理解和把握，才能在實(shí)際的運(yùn)用中做到心中有數(shù)，應(yīng)付裕如。