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考研英语语法重难点精解之:不定式(1)
作者:佚名  文章来源:本站原创  点击数  更新时间:2012-6-8 9:52:14  文章录入:teng91  责任编辑:teng91

  动词不定式是一种非谓语动词,在句中不能单独作谓语。

  一、不定式的时态(Tense)

  以动词do为例:

  语态 时态 主动 被动 一般式 to do to be done 完成式 to have done to have been done 进行式 to be doing 在上述表格中:

  (1) 不定式的一般式表示的动作与谓语动词表示的动作或状态同时发生,前后紧接发生或在谓语动词的动作或状态之后。

  例句: Nobody saw him to come into the office, for three of us were all busy with our own affairs.(saw和came into两动作同时发生)

  分析: 该句是复合句。从句用for引导表原因。

  译文: 没有人看见他走进办公室,因为我们三个人都在各自忙碌着自己的琐事。

  例句: The Smiths have invited me to go to their family party next Sunday, but I am afraid that I will be busy by then.(to go to...明显在谓语动词have invited之后)

  分析: 该句是并列句。

  译文: 斯密斯一家人已经邀请我下周日参加他们的家庭聚会,但是我担心到时脱不开身。

  (2) 不定式的完成式表示的动作发生在谓语动词表示的动作之前,可以用下述句型加以说明,在句型It is said/believed/reported/thought/that sth. /sb....中,可以用不定式的完成式来相互转换,即sb. /sth. is said/believed/reported/thought to be/to be done/to have done/to have been done。

  例句: The local health organization is reported to have been set up twentyfive years ago when Dr. Audon became its first president.(to have been set up发生在be reported 之前)

  分析: 该句是复合句。when Dr. Audon became its first president是修饰twentyfive years ago的定语从句。

  译文: 据报道,这个地方卫生组织25年前就成立了,那时Audon博士就担任了首任主席。

  例句: The Bunsen bumer is so named because it is thought to have been invented by Robert Bunsen, who was German by birth.(to have been invented发生在be thought之前)

  分析: 该句是复合句。because引导一原因状语从句,定语从句who was German by birth 修饰Robert Bunsen。

  译文: 本生灯的得名是因为人们认为它是由罗伯特·本生发明的,罗伯特·本生生于德国。

  (3) 不定式进行式表示动作正在进行,与谓语动词的动作同时发生。

  例句: They are said to be building another bridge across the river in that country. (to be building所表示动作与are said同时发生)

  分析: 该句是简单句。

  译文: 据说,他们正在那个国家架设另一座大桥。

  二、不定式的用法

  (一)充当主语

  例句: It is naive to expect that any society can resolve all the social problems it is faced with once for all. (2001年第16题)

  分析: 该句是复合句。it是形式主语,真正的主语是to expect that any society...,it is faced with是修饰problems的定语从句,其前省略了作宾语的关系词。

  译文: 期盼任何一个社会能够一劳永逸地解决它所面临的各种社会问题的想法太天真了。

  例句: It would be a shame to raise prices too much because it would drive away the young people who are Stratford’s most attractive clientele.(选自2006年Text 2)

  分析: 该句是复合句。其中it是形式主语,真正主语为to raise prices too much,because 后引导一状语从句,定语从句who are Stratford’s most attractive clientele修饰people。

  译文: 把票价抬得太高是不合理的,因为这会赶跑斯特福特镇最能吸引住的客源——年轻人。

  (二)充当宾语

  例句: In that country, guests tend to feel they are not highly regarded if the invitation to a dinner party is extended only three or four days before the party date.

  分析: 该句是复合句。从句they are not highly...作feel的宾语,to a dinner party是一介词短语修饰invitation。

  译文: 在那个国家,如果仅仅提前三四天才向客人发出赴晚宴的请柬,客人们会感到他们不太受尊重。

  例句: Scientists jumped to the rescue with some distinctly shaky evidence to the effect that the insects would eat us up if birds failed to control them. (2010年第46题)

  分析: 该句是复合句。句子的主干是scientists jumped to the rescue with some distinctly shaky evidence, 后接that引导的同位语从句,介词短语with some distinctly shaky evidence作状语,修饰谓语动词jumped to,if引导一个条件状语从句,to the effect that意为“大意是……;主要内容是……”。

  译文: 科学家们立即拿出某些明显站不住脚的证据来补救,大致说的是如果鸟类不能控制害虫的话,害虫就会把我们人类吃掉。

  另外:如果不定式作宾语,其后又接补足语时,要用it作形式宾语,而将真正的宾语(即不定式)置于补足语之后,同样,如果动名词作宾语,其后再接宾语补足时,要用it作形式宾语,而将真正的宾语(即动名词)置于补足语之后。

  例句: The brain finds it best to keep smell receptors available for unfamiliar and emergency signals such as the smell of smoke, which might indicate the danger of fire.

  (选自2005年Use of English)

  分析: 该句是复合句。定语从句which might indicate the danger of fire修饰the smell of smoke, to keep smell receptors...是真正的宾语。

  译文: 大脑会使气味接收器随时接收不熟悉的和紧急的信号,例如烟味,因为它可能意味着有火的危险。

  (三)充当表语(在系动词be, seem, appear, become之后)

  例句: Later, this idea became to be known as the SapirWhorf Hypothesis, but this term is somewhat inappropriate. (选自2004年Part B)

  分析: 该句是并列句。

  译文: 随后,此观点成为著名的萨丕尔—沃尔夫假设,但这一说法并不恰当。

  例句: Many consumers seem to have been influenced by stockmarket swings, which investors now view as a necessary ingredient to a sustained boom.(选自2004年Text 3)

  分析: 该句是复合句。which investors now view as...是一修饰stockmarket swings的定语从句,短语view...as...意为“把……看作”。

  译文: 许多消费者似乎受到股市大幅度起落的影响,而现在投资者认为这些起伏是一个持续增长阶段的必要因素。

  (四)充当定语

  作后置定语,即位于被修饰名词之后,有时与所修饰的名词逻辑上是动宾关系,如果不定式是不及物动词,后面应加介词。

  例句: He asserted, also, that his power to follow a long and purely abstract train of thought was very limited, for which reason he felt certain that he never could have succeeded with mathematics. (2008年第47题)

  分析: 该句是复合句。主干部分是He asserted that ...。 his power...limited是asserted的宾语从句,其中不定式to follow a long and purely abstract train of thought作定语修饰power, for which引导的非限制性定语从句修饰前面整个句子,在非限制性定语从句中又包含了一个由that引导的宾语从句。

  译文: 他坚持认为自己进行长时间纯抽象思维的能力十分有限,由此他也认定自己在数学方面根本不可能有大的作为。

  例句: And the best way to learn how to encode information meaningfully, Ericsson determined, was a process known as deliberate practice.(选自2007年Text 1)

  分析: 该句是简单句。Ericsson determined作插入语,known as...作后置定语,修饰process, to learn how to encode information meaningfully作后置定语修饰the best way。

  译文: 埃里克森认为,学会如何去编辑有意义信息的最好方法是众所周知的有意识练习的过程。

  (五)充当状语(表示目的、结果、原因)

  例句: The vocabulary and grammatical differences between British and American English are so trivial and few as hardly to be noticed. (1997年第10题)

  分析: 该句是简单句。介词短语between British and American English修饰differences,so as to do引导的不定式作结果状语。

  译文: 英式英语和美式英语之间的词汇和语法区别甚微,人们几乎注意不到。

  例句: Greatly agitated, I rushed to the apartment and tried the door, only to find it locked.(2000年第2题)

  分析: 该句是简单句。过去分词agitated在句中作主语补足语,only to find...在句中作状语,表示结果。

  译文: 怀着极大的不安,我跑回公寓,推了推门,结果却发现门是锁着的。

  例句: Some use them to keep a close watch on the demand for their line of work or gather information on compensation to arm themselves when negotiating for a raise.

  (选自2004年Text 1)

  分析: 该句是简单句。to keep a close watch on ... of work和(to)gather information on compensation都作目的状语,是some use them的目的。to arm themselves则是gather information on compensation的目的状语,when negotiating for a raise的完整形式应是when they are negotiating...。

  译文: 有人便借它严密关注自己行业的需求情况,或为加薪谈判搜集相关的加薪信息。

  (六)充当补足语

  1. 充当宾语补足语

  (1)有些及物动词宾语后常接不定式作宾语补足语,构成复合宾语,如ask, advise, allow, command, compel, enable, encourage, expect, invite, tell, force, wish, want, like, oblige, order, permit, prefer, persuade, remind, request, require, send, warn, cause, trouble, urge, instruct, help, lead, press, drive等。

  例句: As a way of coping with the mails while they were away, the Johnsons asked the cleaning lady to send little printed slips asking the senders to write again later.

  (1999年第28题)

  分析: 该句是并列句。分词短语asking the senders to write again later修饰slips,介词短语As a way of coping with the mails在句中作状语。

  译文: 作为他们外出时处理邮件的一种方法,约翰逊一家让清洁女工给写信人寄去事先印好的便条,让他们以后再来信。

  例句: “Do we really want railroads to be the arbiters of who wins and who loses in the market place?” (选自2003年Text 3)

  分析: 该句是复合句。其中who wins and who loses...在句中作介词of的宾语。

  译文: “难道我们真的要让铁路公司成为决定市场上谁兴谁衰的仲裁者吗?”

  (2)下列动词接不定式作宾语补足语时常省略不定式符号to。如:see, watch, observe, notice, feel, hear, perceive, smell, look at, listen to, have, make, let等,但以上动词用于被动语态时,要加上to。

  例句: A turbulent business environment also has senior managers cautious of letting vague pronouncements cloud their reputations. (选自2011年Text 2)

  分析: 该句是简单句。cautious of letting vague pronouncements cloud their reputations在句中作宾语senior managers的补足语,而cloud their reputations又作宾语vague pronouncements的补足语,cloud前省略了to,其意为“使混乱,玷污”。

  译文: 一种动荡的商业环境同样使得高管们小心谨慎,以避免模糊的表态有损他们的声誉。

  例句: He was let to come in and sit with other workmates who had already completed their work.

  分析: 该句是复合句。定语从句who had already completed their work修饰other workmates。

  译文: 有人让他进来和那些已经做完活计的工友们坐在一起。

  (3)不定式在介词except,but后作宾语时,其前有动词do的某种形式要省去to,反之加上to。

  例句: My mother alone is in the railway station, so she has nothing to do except/but wait for me.

  分析: 该句是并列句。

  译文: 母亲一个人在车站,所以除了等我外,她无事可做。

  例句: That was so serious a matter that I had no choice but/except to call in the police.

  分析: 该句是复合句。第二个that后引导一个状语从句,表示结果。

  译文: 问题过于严重,于是除了给警察打电话外,我别无他法。

  2. 充当主语补足语把带有宾语补足语的谓语动词转变成被动语态时,原来的宾语补足语也转变成主语补足语。

  例句: He wasnt asked to take on the chairmanship of the society, being considered insufficiently popular with all members. (1998年第9题)

  分析: 该句是简单句。分词being considered...在句中作状语表示原因,相当于because he had been considered insufficiently...;to take on为主语补足语。

  译文: 考虑到他不能受到每个成员的欢迎,所以没有邀请他担任协会的主席之职。

  例句: We are thus led to distinguish, within the broad educational process which we have been so far considering,a more formal kind of education—that of direct tuition or schooling. (2009年第50题)

  分析: 该句是复合句。句子主干结构是we are thus led to distinguish a more formal kind of education, within the broad educational process which we have been so far considering 在整个句子中作状语,其中which引导一个定语从句,修饰the broad educational process;破折号后的内容作a more formal kind of education的同位语。

  译文: 因此,这就使得我们得以在一直讨论的广义的教育过程中,进一步区别出一种更为正规的教育,即直接教学或学校教育。