1) 可以指主语，依动词词义的不同。

2) 可以指主语以外的其他名词或代词成分，特别是宾语。可以指固定身份，一时的、新得到的或失去的身份或性质。

• We regard the whole thing as a joke.我们把这件事全看成玩笑。
• As a historian this kind of assertion always amuses me.我作为一个历史学家，这一类的主张总是使我觉得好笑。
• He uses his umbrella as a walking stick.他拿他的雨伞当拐棍使。
• They promised to back him as the leader.他们答应支持他当领袖。
• The board of directors fired him as the chief engineer.董事会解除了他的总工程师职务。
• The alibi eliminated him as a suspect.由于有当时不在场的证明，他就被解除了怀疑。
• As an outsider, the Koran strikes me as a reforming book, trying to return Judaism and Christianity to their origins, much as reformers attempted to do with the Christian church centuries later. (Tony Blair, Foreign Affairs, Jan. /Feb., 2007)对于我这样一个身处其外的人来说，《古兰经》给我的印象是一本改革的书，它要让犹太教和基督教回到自己的本源，正像几个世纪以后基督教会内部的改革派所企图做的那样。

3) 甚至可以指 of 后的名词或指主有代词所代表的人称。

• his duty as a father他做父亲的责任
• my honor as a soldier我的军人荣誉
• his life as a composer他的作曲家生涯
• test of English as a second language第二语言英语测验
• Her father's income as a computer programmer...(The New York Times, Sept. 30, 2007)她父亲做电脑程序设计师的收入…
• As British ambassador in that period, his advice to London heavily favoured the opposition.作为那个时期的英国大使，他向伦敦提出的主张明显地偏向在野派一方。
• As a doctor, my duty is to preserve life.作为医生，我的义务就是维护生命。
• Do your duties as a priest extend beyond the church?你作为牧师的职责是否超出教会之外？
• Ha! Say no more! You have my word as a gentleman — it shall be so! (John Darnton, The Darwin Conspiracy, pp.140-141)哎呀！别再说了。你就听我的君子诺言吧 ——就这样办！
• As the Leon County supervisor of elections, Jon Sancho's job is to make sure voting is free of fraud. (The Washington Post, Jan. 22, 2006, A6)作为莱昂郡的选举督察员，桑却的任务是保证选举不出现舞弊现象。
• Such ideas were drummed into his head as a battalion commander.这些想法都塞进了他这个营长的头脑里。
• Gold has always been at the heart of Mexico—from the ancient Aztec and Inca civilizations to European conquests started by Cortés to its modern day struggles as a nation.黄金向来是墨西哥的核心——从古代的阿兹台克和印加文明，到科尔特斯所开拓的欧洲人征服时期，到现代它作为一个国家艰苦奋斗的时代。
• His inexperience as a commander was revealed most pathetically at the Casablanca conference... (US News & World Report, Oct. 28, 2002, p.46)他的缺乏作战指挥经验，在卡萨布兰卡会议上暴露得最为狼狈…
• The Korea-US FTA will serve as an opportunity for Korea to solidify its position as a new financial hub in Northeast Asia and to globalize its economy one step further.韩美自由贸易协定将为韩国提供一个机会，巩固它作为东北亚一个新的金融中心的地位，并进一步使其经济全球化。
• South Africa spends nearly 1 percent of its gross domestic product on science—about five times the African average. Reflecting its needs as a developing country, much of that goes toward research in agriculture, health and biotechnology.(The Washington Post, April 24, 2006; A06)南非的国民生产总值将近有百分之一用于科学，大约是非洲平均数的五倍。其中很大部分用于农业、卫生和生物科技的研究，这正反映出南非作为一个发展中国家的需要。

有时候甚至 his, her, their 之类的主有形容词不出现，也可以用 as。

• Had Eisenhower shunted aside all distractions to focus on seizing Tunis with a battle captain's fixed purposes, the coming months might have been different. But a quarter century's habits as a staff officer, with a staff officer's meticulous attention to detail and instinctive concern for pleasing his superiors, did not slough away easily. (US News & World Report, Oct. 28, 2002, p.46)假如当时艾森豪威尔把分心的事情统统放到一边，抱着战地指挥官的固定目标，一心一意考虑如何攻占突尼斯，往后几个月的情况就会大不相同。但是，他二十多年担任参谋人员养成了习惯，作为参谋人员，总是事无巨细均在关心之列，而且还养成了博取上级欢心的本能，凡此种种习惯，是不会轻易丢掉的。

4) 可以指主语的行动，作为对它的补充说明或评价。

• He builds houses as a hobby.他以盖房子来作为业余消遣。
• He undermined the regime as the unintended consequence of his efforts to reform it.他设法要改革这个制度，但原先想不到的后果是破坏了它。
• Court deputies, as a general rule, are uniformed and armed.法警照例通常是穿着制服并且携带武器的。
• David Ridgen had been assigned by CBC Television to do a new documentary on the "Mississippi Burning" case. As part of his research, he had watched a 1964 CBC piece on the murders. (The Washington Post, Jan. 25, 2007)大卫·里真是由 CBC 电视台指派拍摄有关“密西西比烧杀案”的纪录片的。作为他的调研工作的一部分，他看过了 CBC 1964 年有关这些谋杀案的片子。
• …as a step towards conversing with her himself,(Darcy) attended to her conversation with others. (Jane Austen, Pride and Prejudice, Chapter Six)…他为了想要慢慢地跟她攀谈攀谈，因此她跟别人谈话的时候，他就留心去听。

5) 对整个事件作补充说明或评价。

• Gas prices fell as a result of Congressional attention to the problem.由于国会重视这个问题，汽油价格下降了。
• All schools were closed as a precaution.作为预防，所有学校都关闭了。

1) as 作为表示“方式如同…一样”的连词，引入一个状语从句，如果 as 前面有否定，这个否定究竟是到达 as 面就停下来，还是一直继续，把 as 及其后面从句的内容也一起否定？应该说，通常情况下，否定的作用是一直贯彻下来，把 as 后面的内容连同 as 前面的内容合在一起全盘加以否定（即使 as 前面有逗号隔开，这个否定作用也越过逗号贯彻到 as 后面）。

• He did not go to office daily, as his father did before him. (Kruisinga)他不像他父亲从前那样每天都去上班。
• Her pregnancy was not seven months long, as he had believed, but only five.她并不如他原先以为的那样怀孕了七个月，而只是五个月。
• Women's desires to connect with others and their emotional accessibility traits were essential strengths，not weaknesses as they were traditionally regarded.妇女要同他人联络的愿望，以及她们在感情上容易触动的特点，是重要的优点，而不是像传统上所认为的那样是弱点。
• It did not matter that Mohamed Atta, the leader of the 9
• 11 terrorists, never met with Iraqis in Prague, as high-level Bush people claimed.“9·11”恐怖分子的头头穆罕默德·阿塔从未像高层的布什亲信所说的与伊拉克人在布拉格会过面，但这不重要。
• But it was another Italian, Alessandro Volta, who found that the electricity came not from the frog, as Galvani had thought, but from the metals.但是另外一个意大利人亚历山德罗·伏尔塔却发现了电并不像加尔万尼所想的那样来自那只青蛙，而是来自金属。
• Working in an open- source world is not without its hardships. There is no toll-free number to call when things don't work, as is the case with packaged software.在一个源头开放的世界里活动，总是免不了遇到种种麻烦。东西不灵了，就不能像买来原装的软件那样有免费电话号码可以查询。
• .... that it was not that that kept me silent: it was the fear that this sudden cessation of pain was not so favourable a symptom as he supposed. (Anne Brontё, The Tenant of Wildfell Hall, Chapter 49)…使我沉默不语的，并不是那个原因，而是我担心，疼痛忽然这样停止，并不如他所推测的那样是个好征状。

但是，也有 as 及其后面内容不受否定的。

• He posed for a few pictures and shook hands—though not with women, as Islamic custom dictates. (US News & World Report, Oct. 2, 2006, p.30)他摆姿势找了几张照片，还握了手，但是按照伊斯兰风俗，没有同妇女握手。
• The Supreme Court normally does not hear any evidence, as is true with all appeals courts.同所有上诉法院一样，最高法院通常不聆听证据。
• Standard treatment is not terribly effective, as is the case with many advanced cancers.正如许多晚期的癌症那样，标准疗法并不十分有效。

此外，有时候 as 前面没有 not 之类的否定，但是有带有否定意义的单词或词组。

• Under the new policy, a film's rating will consider all tobacco use, rather than just teenage smoking, as in the past. (The New York Times, May 11, 2007, C1)按照新的办法，影片的分级，要将一切吸烟镜头都考虑在内，而不是像过去那样只考虑青少年吸烟的镜头。
• The government would allow outsiders to own 100％ of local companies by June rather than by the end of the year as had been earlier contemplated.政府可能到六月而不是按照原先预定的那样要到年底才让外来人百分之百地拥有本地公司。

有时候 as 前面既有否定词语也有肯定词语，此时要注意弄清楚 as 向前管到何处。

• While Iraq's president is optimistic about his country's future, Iran's president remains intransigent in his refusal to halt nuclear-related activities as demanded by the United States as a precondition for talks. (Newsweek, Oct. 2, 2006, p.31)伊拉克的总统对本国的前途表示乐观，而伊朗的总统则仍然坚持拒绝按照美国提出的谈判先决条件停止与核有关的活动。

这里的 as demanded 向前只管到 to halt，不能继续往前管到 refusal（如果管到 refusal，意义就相反，变成“美国要求伊朗拒绝停止核活动”，这是荒谬的）。

• The White House is betting that the steps it has taken to address the housing and financial crises will be enough to avert a recession without resorting to a major tax cut or new spending, as leading economists in both parties have urged. (The Washington Post, Dec. 21, 2007)白宫正在估计，它为了对付房贷与金融危机而采取的步骤，将足以避免衰退，而不必照两党的高级经济学家们所敦促的那样实行大幅度减税或新增支出（as 管 resorting，不管 avert a recession）。

2) as 如果引入表示“正当…之时”的时间状语从句，此时从句中的谓语动词即使用现在或一般过去时，不用进行式，也仍然表示无限延续的动作，不是表示瞬时完成的动作。用第二类动词（“活动动词”）时，固然表示正在过程中，没有终点可言。即使用第三类动词（“趋成动词”）时，本来通常用一般过去时这类动词表示动作已经到达了终点，但是在 as 引入的时间状语从句中却是例外，所表示的是动作仍在进行过程中。

• Even as the ink on the treaty dried, a final struggle was taking shape over the vast lands of the West. (American History Made Simple, p.33)条约墨汁未干，争夺西部大片土地的一场最后的战斗就已经在开场（注意：这里的 dried 不是“干了”，而是“正在逐渐干着但未全干”，as 表明了过程在进行中，否定了过程的结束）。
• The clack of high heels can be heard as she crosses the yard.她穿过院子时，可以听到高跟鞋的咯咯声。
• On sidewalks a tide of hurrying inbound office workers swirled around Sam and Celia as they strolled.萨姆和塞莉娅在人行道上漫步时，被潮水般的一大堆往里走的办公室工作人员团团卷在中间。
• Antoine Ghanem... died when a bomb in a parked car went of as he drove by in a Christian suburb of the capital. (The New York Times, Sept. 20, 2007, A1)加涅姆正在驱车经过首都一个基督教郊区时，一辆停泊的汽车里炸弹爆炸，他因而丧生。
• They had encountered each other in a corridor where others were passing as they talked.他们是在一条走廊上碰面的，交谈时别的人就从他们身边走过。
• As FDA's examination proceeded, scientists from the pharmaceutical companies would be called in, perhaps to explain some of the submitted material or to add even more.当食品药物管理局的审查在进行中时，医药公司的一些科学家往往被喊去，也许是要对原先提供的材料作出说明，或者再补充更多的材料。

因此，as 引入的时间状语从句（谓语动词用一般时），往往相当于中文的“随着”（这是一个很简单的用法，不必麻烦去找复杂的英语说法来翻译“随着”）。

• As time went on, the prediction of Dr. Gould seemed increasingly and sadly to be true.随着时间推移，古尔德博士的不祥预言就越来越显得不幸而言中。
• As the world warms, the United States will face more severe thunderstorms with deadly lightning, damaging hail and the potential for tornadoes. (AP, Aug. 30, 2007)随着地球变暖，美国将遇到更多的严重雷阵雨，带有致命的闪电、破坏性的冰雹以及潜在的龙卷风。
• As his computer expertise grew, he began making Internet connection all over the world.随着他的电脑技能日益提高，他就开始通过互联网联上了全世界。
• Therefore, as months went by with no decision made, his frustration grew.因此，随着时间一个一个月过去，事情悬而未决，他就越来越心焦如焚。
• Resources produced in the United States play a leading role in meeting our domestic energy needs. They will continue to do so as our economy grows and Americans' demand for energy increases. (ExxonMobil ad, The New York Times, OP-ED, Nov. 29, 2007, A31)美国国内生产的资源，对于满足我们国内的能源需求，起着主导作用。今后，随着我国经济的发展，随着美国人对能源需求的增加，国内生产的资源将继续起着主导作用。

3) 从上可见，as 作为主从连词引入时间状语从句时，它对从句中谓语动词的“体”可以起“延续化”的影响，不但可以使第二类动词（延续的“活动动词”）免用进行时，也可以使第三类动词（延续但有必然终点的“趋成动词”）转化为第二类而避免用进行时，甚至可以使第四类动词（瞬时的“达成动词”）“延续化”（把短促的行动用“慢镜头”显示）。

• As I left the house I remembered the key.

我正要出门时，还没有完全出门，就想起了钥匙（门还没有锁上，还来得及回去拿），相当于 While I was leaving the house I remembered the key. 本来 leave 是个瞬时的短促动作，但是在这里被 as 这个“慢镜头”拖长了。反之，如果说 When I left the house I remember the key, 意思就变为“我刚出门，门锁上了之后，才想起了钥匙（但为时已晚）”。不过，while 后面之所以要说 was leaving，而不能像 as 后面那样说 left，是因为动词 leave 是瞬时性的“达成动词”（第四类），如果动词是延续性的“活动动词”（第二类），while 从句中就不一定非用进行时不可，也可以同 as 从句一样用一般时。

• She cooked dinner while the kids watched (were watching) TV.孩子们边看电视，她边做晚饭。

或者如果主句动词是延续的，while 从句动词即使是瞬时的也可以变成“慢镜头”。

• We waited a few minutes outside his office while he finished up his meeting.我们在他办公室外面等了几分钟，让他把会开完。

又例如：

• They sat down and watched as the commercial ended.他们坐了下来看，一直看到广告播送完。

这里的 end 明明是个瞬时体的第四类动词，但是在 as 影响下，被拖长了，带有“一直进行着直到结束”的意思，此时这个 as 也可以用 while 来代替。

4) as 后面如果引入表示“就像…那样”、“照…那样”的方式状语从句，这个从句的标准结构，就是句子成分不完全，或是缺主语，或是缺宾语，或是缺表语，或是缺宾语补足语（也有学者认为在这里 as 兼管代替了所缺的成分，尤其是主语）。正是这个短缺，使得从句同主句的关系更紧密。下面分述各个句子成分缺位的情况：

5) 也有 as 从句完整，不缺少任何成分的，这种情况，往往出现在两件没有相同成分但可以作比拟的事情上。

• They hunted him as a tiger stalks his prey. 或 As a tiger stalks his prey, so they hunted him.

有时候骤然看来 as 从句完整，但其实省略了一个状语（状语不是句子的必要成分，所以缺了一下子看不出来），例如苏联 1978 年出过一本用英文写成的俄语课本，书名是 Russian As We Speak It。骤然看来，as 从句中，主语、谓语、宾语都齐全，但是其实在意义上缺了状语 how（结构上 how 也放不进去），这就不是两件事情相比拟了。

6) as 后面的从句，如果实际意义上所缺的成分是 how（就像上面 Russian As We Speak It 的例子那样），可以从后面的主句看出它是方式状语从句。此时主句往往以 so 开头，而且主谓语颠倒。

• As he sat then, so had he sat for a whole day and a whole night. (E. Phllips Oppenheim, The Yellow Crayon, Chapter I)他这个样子坐着，已经坐了一整天一整夜了。

7) as 后面不是句子，而是一个过去分词。有 as 与没有 as 的区别在于：没有 as，这个过去分词是表示对前面的名词有长远的、固定的修饰作用，而有 as，则表示这个修饰作用只在当前这个具体场合有效。

• their position, as opposed to ours他们的立场同我们的相对照（当前说话时拿来相对照，不是一直都是对立的）
• the English language as spoken in America美国人说的英语（当前暂时把英语缩小到美国范围，这同对一般意义的美国英语采取的观察角度不完全相同）
• Paris as seen by tourists is a very different city.如果用观光客的眼光来看巴黎，那就是另一个大不一样的城市了（当前说话时临时提到观光客，巴黎并不是一直被这样看的）。
• This report only discusses unemployment as measured by statistics but not as experienced by actual people.这个报告，仅仅从统计数字的测定，而不是从人们实际的感受，来谈论失业问题（当前说话时谈到失业问题在眼前这个报告中如何测定，并非这个问题向来都是这样来测定）。
• Tests for safety and efficacy, as required by law, could begin in the United States.按照法律要求对药物进行安全与功效测试，可以在美国着手进行（进行测试，当前的着眼点就是满足法律的要求，这是当前的焦点，尽管法律要求是一贯的、普遍的）。
• The phrase "regime change" is associated with the doctrine of preventive war as applied to Iraq.“改变政权”，是同先发制人开战主义应用于伊拉克之时形影相随的一个用语。

这个 as + pp 词组，有时候不一定要放在一个名词后面作为定语，它也可以作为一个状语词组，表示“按照…”、“每当…之时”。

• Reseal as required.请按需要重新封紧。
• They can help as needed.必要时他们可以帮忙。
• Take two aspirins as needed.必要时服用两片阿斯匹林。

如果修饰的事件已经发生，as + pp 则可以是“照原来说的办了事”的意思。

• He went as agreed.他如约去了。
• They came as promised.他们履行诺言前来了。

也可以作为对全句内容的一个概括说明。

• A bolt of lightning strikes, as seen from Bogart Road in Huron Township, Ohio, Wednesday, June 21, 2006, the first day of summer.夏季的第一天 2006 年 6 月 21 日星期三从俄亥俄州休伦镇波格特路看到的一下闪电（照片说明）。

8) as with 后面可以接上一个与主语语义同格的名词成分，表示这个成分所代表的事物与主语所代表的事物有相同的遭遇。

• As with many other adventurous foreigners later, he was forbidden to leave.正如日后的许多外国冒险家所遭遇的那样，他当时也被禁止离开。

9) as 在一些特殊的结构中，可以表示“虽然”。分述如下：