而考生复习英语，语法也是必通关的基础项目之一。根据历年来看，总结三大难点语法为大家详解，一起来看下。

【as用法】

一、as引导定语从句

as引导定语从句时，既可以引导限定性定语从句，又可以引导非限定性定语从句。区分as引导定语从句和其它从句的关键特征是：as引导定语从句时在从句中做成分，通常做主语或宾语。

1、as引导限定性定语从句。

如从句所修饰的名词前有such、the same、as出现，后面的定语从句将由as引导，形成such...as，the same...as，as…as这样的固定结构，译为“和……一样”。

例1：I never heard such stories as he told.

我从未听过他所讲的那样的故事。

例2：He’ll repeat such questions as are discussed in the book.

他将重复书中讨论过的问题。

例3：They made the same mistake as others would have made on such an occasion.

他们犯了和其他人在这种场合下会犯的同样错误。

2、as引导非限定性定语从句。

as引导非限定性定语从句，往往指代一整句话，通常表示“正如”的意思。as引导的非限制性定语从句位置相对比较灵活，可以位于先行词之前、之后或中间。

例：As is known to everybody, the moon travels round the earth.

众所周知，月亮绕着地球转。

二、as引导时间状语从句

as引导时间状语从句多用于口语，强调“同一时间”或“一先一后”，有时还有“随着”的含义。

例1：As I was going out, it began to rain.

当我出门时，开始下雨了。(as强调两个动作紧接着发生，不强调下雨的特定时间。)

例2：As time goes on, he will understand what I said.

随着时间的推移，他会理解我所讲的话。

三、as引导原因状语从句

as表示“因为”，与because相比，较口语化，所表达的原因语气较弱，所表的原因比较明显，或是已知的事实。

例1：As the weather is so bad, we have to delay our journey.

因为天气太糟糕，我们不得不推迟旅行。

例2：Any new source of energy will be very welcome, as there is already a shortage of petroleum.

任何新型能源都将大受欢迎，因为石油已经出现短缺。

四、as引导方式状语从句

as表示“按照”，“以……方式”，“像……一样”，“正如”。

例：Do as the Romans do when in Rome. 入乡随俗

注：as在引导方式状语从句时，还常出现在一个固定的类比结构中：(just) as …, so…。这一句型表示类比，基本含义是“正如……，所以……”。

例：Just as virtue is its own reward, so is vice its own punishment.

善有善报，恶有恶报。

五、as引导让步状语从句

as可以表示“尽管”，“虽然”，引导让步状语从句，但必须构成倒装。让步状语从句倒装规则有两类：

1、 形容词/副词/分词/名词(无冠词)/介词短语等+as+主语+谓语动词，主句。

例1：Much as I like you, I couldn’t live with you.

我尽管很喜欢你，却不能和你在一起生活。

例2：Child as he is, he knows to help others.

尽管他是个孩子，他懂得帮助别人。

2、动词原形+as+主语+助动词(may/might, will/would, can/could, do/does/did)，主句。

例：Try as we may, we cannot sense directly the television signal sent out from the broadcast station.

尽管我们费了很大的劲，也无法直接觉察发射台发出的电视信号。

六、as引导比较状语从句

as引导比较状语从句，其基本结构是as…as。前一个as是副词，后一个as是比较状语从句的连词。否定结构为not so much … as …。

例1：Small as it is, the ant is as much a creature as are all other animals on the earth.

尽管蚂蚁很小，但是它同地球上的任何其他动物一样，也是一种动物。

例2：It was not so much the many blows he received as the lack of fighting spirit that led to his losing the game.

与其说是他受到了许多打击，还不如说是缺乏斗志使他输掉了比赛。

【that用法】

一、that 作限定词或代词

that可以作限定词或代词连接名词或名词短语，也可单独使用，用以指代人或者物。此外，that不仅可以指代单独的人或物，还可以指代一句话。

例：Furthermore, in the early days of long line fishing, a lot of fish were lost to sharks after they had been hooked. That is no longer a problem, because there are fewer sharks around now. [2006, text3]

分析：

A.分析句子结构。Furthermore, in the early days of long line fishing, a lot of fish were lost to sharks //after they had been hooked. That is no longer a problem, //because there are fewer sharks around now.

个句子的主句为a lot of fish were lost to sharks，介词短语in the early days of long line fishing作状语，after引导时间状语从句。第二个句子主句是That is no longer a problem, that为代词，because引导原因状语从句。

B.分析that指代。that指代句话，“a lot of fish were lost to sharks after they had been hooked”，其中after引导时间状语从句。

C.译文：而且，在使用多钩长线捕鱼的初期，许多鱼被钩住后又被鲨鱼夺走。这不再是一个问题，因为附近的鲨鱼更少了。

二、that作副词表示程度，相当于so

例：It isn’t all that cold. 天没有那么冷。

三、that作连词引导各类从句

(一)that引导名词性从句

that后面连接一个完整的陈述句，可以位于主语、宾语、表语或同位语的位置，分别引导主语从句、宾语从句、表语从句和同位语从句。此时，that没有实意，而且不在从句中做任何成分。that引导主语从句和同位语从句时不可以省略。

例1：That the plates are moving is now beyond dispute. (主语从句)

地球板块是在漂移的，这一事实毋庸置疑。

例2：The truth is that everyone should take care of orphan, not just the authorities.(表语从句)

事实是，所有人都应该照顾孤儿，而不仅仅是完全由政府承担。

例3：All people believed that it was right to rescue the temple. (宾语从句)(注：that可以省略)

所有人都认为拯救古庙是正确的。

例4：The students expressed their hope that they could be admitted by that university.(同位语从句)

学生们表达了他们向被这所大学录取的愿望。

(二)that引导定语从句

that引导定语从句，在从句中充当主语、表语或者宾语，既可以指代人，也可以指代物。that在定语从句中作宾语时，引导词that可以省略。

例1：The professor that you admire most will visit our university next month.

你敬仰的那个教授下月会到我们学校参观。

例2：This is one of the subways that will be put into use in two years.

这是未来两年内将开通的地铁之一。

例3：I have nothing that is worth reading.

我没有什么值得一读的东西。

(注：当先行词中有不定代词、形容词最、序数词或者先行词被the only，the very等限定词修饰等情况下，定语从句引导词也只能用that。)

(三)that与其他单词结合引导状语从句

that可以和其他单词结构共同引导状语从句，例如such...that，so...that等引导结果状语从句，in order that，so that等引导目的状语从句，in that，now that，on the grounds that等引导原因状语从句，suppose/supposing/assume/assuming/provided/providing that，on condition that等引导条件状语从句等。

例1：She has made such rapid progress that before long she could pass the exam.

她进步很快，不久就能通过考试的。

例2：You should make full use of this opportunity so that you can get rich experience.

你应该充分利用这次机会，以便获得丰富的经验。

例3：Supposing that you were in my position, what would you do?

如果你在我的位置，你会怎么做?

例4：On condition that you were lost in the desert, you should ask for help as soon as possible.

如果你在沙漠中迷路，你应该尽早寻求帮助。

(四)that引导强调句

“It is/was+被强调部分+that从句”是高频使用的一种强调句型，其中被强调部分可以作从句的主语、宾语和状语等。强调句中去掉“it is/was”和“that”后，句子成分和语义仍然完整。

例：It was after the war was over that Einstein was able to come back to his research work again.

战争结束后爱因斯坦才能重新进行他的研究工作。

【倒装句】

一、全部倒装

(一)there be句型

有时一些表示存在意义的不及物动词也可用于该句型，如：stand， lie， exist， live， remain，appear， come， happen， occur， rise等。

例句：Generally, there was a belief that the new nations should be sovereign and independent states, large enough to be economically viable and integrated by a common set of laws. (选自2007年Use of English)

分析：该句是复合句，其中a belief与that the new nations should be sovereign and independent states互为同位语关系，形容词短语large enough to be...作定语修饰states。

译文：他们普遍认为新生的国家是拥有主权和完全独立的国家，大到经济上可运行良好，并由一套共同法律让各个新的独立国家联合起来。

(二)表示方向、地点的状语等词置于句首

here， there， up， down， away， in， out， off等位于句首时，往往主谓倒装。

例句： Here is an example, which I heard at a nurses convention, of a story which works well because the audience all shared the same view of doctors.(选自2002年Text 1)

分析：该句是复合句，which I heard at a nurses convention和which works well共同修饰story。

译文：举个例子，在一次护士大会上，我听到了一个效果很理想的幽默故事，因为听众都对医生持有相同的看法。

(三)作表语的形容词或分词置于句首

例句： Lying unconsciously under the tree was an old man aged 75.

分析：该句是简单句，aged 75修饰an old man，作后置定语。

译文：一位75岁高龄的老人躺在树下，已经不省人事。

二、部分倒装

(一)否定词或具有(半)否定意义的词或词组置于句首作状语

如：never， scarcely， hardly， rarely， seldom， little， no sooner...than，hardly...when，scarcely...when (before)， not only， in no case (in no way， at no time， on no account， by no means，under no circumstances，in no respects)(决不，在任何情况下都不)，no longer/no more (不再)。

例句： Television is one of the means by which these feelings are created and conveyed and perhaps never before has it served so much to connect different peoples and nations as in the recent events in Europe. (2005年第46题)

分析：该句是复合句，and前是一复合句，定语从句by which...修饰the means，后一分句中never置于句首引起倒装。

译文：电视是制造和表达这些情绪的方式之一，在加强不同民族和国家之间的联系方面，电视也许还从来没有像在欧洲事务中那样起过如此大的作用。

(二)only+副词/介词短语/状语从句(句首状语由only修饰)

例句： Only recently did linguists begin the serious study of languages that were very different from their own. (选自2004年Part B)

分析：该句是复合句，that were very different from their own是修饰languages的定语从句。

译文：直到最近，语言学家才开始认真研究与他们自己所掌握的完全不同的语言。

例句： Only gradually was the byproduct of the institution noted, and only more gradually still was this effect considered as a directive factor in the conduct of the institution.(2009年第47题)

分析：该句是由and连接的两个并列简单句，两个分句都是以only开头的倒装句，在前一分句中，主干部分是the byproduct of the institution was noted， only gradually修饰noted;在后一分句中，主干是this effect was considered...，其中only more gradually修饰considered, as a directive factor作主语this effect的补足语，介词短语in the conduct of the institution作directive factor的后置定语。

译文：人们只是逐渐地认识到制度这一副产品，而在运行这种制度的过程中，认识到这种效果具有指导性作用的时间则更加缓慢。

(三)条件从句中省略if

在虚拟语气中，条件从句if省略时，倒装到主语前的是助动词should，had和系动词were。

例句： Were the Times Co. to purchase another major media company, there is no doubt that it could dramatically transform a family run enterprise that still gets 90% of its revenues from newspapers. (1999年第13题)

分析：该句是复合句，were the Times Co. to purchase是一省略if的倒装句，that it could dramatically...enterprise是doubt的同位语，而that still gets 90% of its revenues from newspapers是修饰enterprise的定语从句。

译文：如果时代公司要收购另一家主流媒体公司的话，那仍旧靠报纸获得90%收入的家族式企业的模式肯定会遭到它大刀阔斧的改革。

例句： Had it not been for the timely investment from the general public, our company would not be so thriving as it is.(1998年第10题)

分析：该句是复合句，had it not been...是一个省略if的倒装从句，整个句子表示混合式虚拟语气，主句表示与现在相反假设，从句表示与过去相反假设。

译文：要不是公众及时投资，我们公司不会像现在这么繁荣。

(四)其他部分倒装情况

表示前面陈述的情况适合于后者，前面是肯定句，后面用so引导;前面是否定句，后面用neither或nor引导，省略倒装句中的助动词在时态和语态形式上与前面句子保持一致。。

例句： Americans no longer expect public figures, whether in speech or in writing, to command the English with skill and gift. Nor do they aspire to such command themselves. (选自2005年Text 4)

分析：该句是由nor引导的并列句。whether in speech or in writing的完整形式是whether they are in speech or in writing，表示让步;介词短语with skill and gift在句中作状语修饰动词command。

译文：美国人不再期望公众人物在演讲或写作时可以娴熟地运用技巧和文采来掌握英语，而人们本身也不这样要求自己。

(五)so...that结构

so...that结构中，“so+状语”位于句首表强调时，使用倒装。

例句： So involved with their computers do the children become that leaders at summer computer camps often have to force them to break for sports and games.(2001年第6题)

分析：该句是复合句，that leaders at summer computer camps...是一结果状语从句，so involved with...置于句首引起倒装。

译文：孩子们对电脑如此着迷，以至于电脑夏令营的组织者们不得不强迫他们停下来做一些体育运动和游戏。

(六)not until置于句首

not until置于句首时，连词until引导的从句主谓不倒装，但主句的主谓结构必须倒装。

例句： Not until you return those books to the library immediately will you have to pay a fine.

分析：该句是复合句。由于not until置于句首，主句will you have to pay a fine是一倒装句。

译文：只有及时还书给图书馆，你才不会受罚。

(七)as， though， no matter how， however引导的让步状语从句

as， though引导的倒装句型为：名词(前不加a或an)/形容词/副词+as+主语+谓语，该结构可用though引导的让步状语从句来替换，译为“虽然…但是”或“尽管…但是”。

例句：Much as I have traveled, I have never seen anyone to equal her in thoroughness, whatever the job.

分析：该句是复合句，其中从句much as I have traveled是一倒装句，短语“equal sb. in sth.”意为“在某方面与他人旗鼓相当”

译文：虽然我常旅行，但我从未见过任何人于任何工作能像她那样一丝不苟。

例句：Odd though it sounds, cosmic inflation is a scientifically plausible consequence of some respected ideas in elementary article physics, many astrophysicists have been convinced for the better part of a decade that it is true. (1998年第75题)

分析：该句是复合句，odd though it sounds是一倒装句，其中it指代cosmic inflation，介词短语in elementary article physics修饰ideas，that it is true在句中作convinced的宾语，另一介词短语for the better part of a decade作状语表示时间。

译文：宇宙膨胀说虽然听似奇特，但它还是基本粒子物理学中一些公认的理论在科学上看来可信的推论。许多天体物理学家十年来一直认为这一论说是正确的。

(八)be+主语+其他(若其他是单数名词作宾语，则名词前不接不定冠词a/an)

这是一开放式条件状语从句，属于特殊倒装结构，表示泛指。该结构可用whether...or结构来替换，同时单数名词前的不定冠词保持不变，可译为“不管/不论……”。

例句：Church as we use the word refers to all religious institutions, be they Christian, Islamic, Buddhist, Jewish, and so on.(2001年第10题)

分析：该句是复合句，be they...是一倒装句，相当于whether they are...。

译文：我们所使用的教堂一词，指的是所有的宗教机构，不管它们是基督教、伊斯兰教、佛教或犹太教等。