专四语法重点总结

下笔如有神读书破万卷

情态动词

1．can 用于否定句cannot(help)but表示不能不，只能（but后跟不带to的动词不定式）2．must 表示禁止，一定不要时的否定式为mustn't 当它表示有把握的推断时意为一定

准是时它的否定形式为can't

3．need doing=need to be done 这个句型表示被动意味

4．need not have done sth 表示本来没有必要做某事（经常考）

虚拟语气

1．It is (high/about/the)time... 谓语动词用过去式指现在或将来的情况表示早该做某事而现在已经有点晚了

2．It is the first(second/third)time后的that从句中，谓语动词要用完成体来表示一种经验

3．as if/though 的虚拟要点

1) 对当时事实的假设，从句谓语用过去式，be动词一律用were

2)对过去事实的假设，从句谓语用过去完成式

3)对未来事实的假设，从句谓语用would+动词原型

不定式做状语主要表示目的、程度、结果、方式。

(1)in order to(do), so as to(do)结构引导目的状语，so as to不能置于句首。如：

(2)so…as to, such…as to, enough…to, too…to结构做程度状语。如：

The solution works only for couples who areself-employed, don't have small children and getalong well enough to spend most of their timetogether.

The vocabulary and grammatical differences between British and American English are so trivial and few as hardly to be noticed.

(3)不定式做结果状语只能出现在句子的末尾，表示不愉快的结果，有时用only加强语气。

常见的不定式动词有find, hear, see, be told, form, give, make, produce等。如：Greatly agitated, I rushed to the apartment and tried the door, only to find it locked.

(4)not/never too…to, too…not to, but/only too…to, too ready/eager/apt/inclined to 表示肯定意义。如：

I am only too pleased to hear from you further. 能再听到你的消息，我太高兴了。

不定式做定语

(1)被修饰的名词前有序数词、形容词最高级或next,last, only, not a, the, very等限定词时，该名词用不定式做定语。如：the first woman to set foot on the moon第一个登上月球的女性。

(2)如果其动词要求不定式做宾语，相应的名词一般用不定式做定语。如：

tendency to do→tend to do, decision todo→decide to do

how it is used.

recognize This book is an attempt to help you use Englishand

下笔如有神读书破万卷

(3)如果其形容词形式要求接不定式做补语，相应的名词一般用不定式做定语。如：

ambition to do “干……的雄心”→be ambitious to do“有雄心干……”

curiosity to do “对……的好奇心”→be curious to do“对……好奇”

ability to do“做……的能力”→able to do“有能力做……”

According to Darwin, random changes that enhance a species' ability to survive

arenaturally selected and passed on to succeeding generation.

(4)表示方式、原因、时间、机会、权利等名词用不定式做定语，这些名词包括：

way, method, reason, time, place, chance, occasion, opportunity, evidence, power, right,movement, drive (运动)，effort等。如：I worked so late in the office last night that I hardly hadtime to catch the last

bus.

We appreciate your efforts to bring about a comprehensive solution to the existingproblem.

(5)不定代词something, nothing, little, much, a lot习惯上用不定式做定语。如：Though we have made great progress, there is still much to be improved.

倒装

固定语序主语+谓语后置

1．句尾焦点和句尾重心2．关键词语的后置

前置与倒装

1)不引起倒装的前置

不引起倒装的前置成分通常是宾语、主语补语和宾语补语。

2) 引起倒装的前置:

主语补语前置时，如主语较长或结构较复杂，就会引起倒装。

前置宾语由not a + 名词或not a single + 名词，就会引起倒装

A horrible mess I have made of it.

Books, I need.

Happy indeed I am

Happy indeed are those who got the tickets to Beijing.

倒装

某些状语的前置会引起倒装: 全部倒装和部分倒装

a. 句首状语为方位词或拟声词，谓语动词为go, come等表示位置转移的动态动词时，通常用全部倒装，主语为代词，不用倒装。

. Lower and lower he bent.

b. 当句首状语为表地点的介词词组时，也会引起全部倒装。

From the wall comes the voice of the doctor.

下笔如有神读书破万卷

c.当句首状语为否定词或带有否定意义的词语时，一般引起局部倒装。

Nowhere else could you find so cheap books.

d.当句首状语为only + 副词, only +介词词组, only + 状语分句构成，也可引起局部倒装。Only through sheer luck did he manage to get some tickets.

e.以关联连词so (…that)开头的句子，引起局部倒装。so+形容词是主语补语的前置；so+副词是状语的前置。

So small was the mark that I could hardly see it.

f.当方式状语、频度状语等移至句首时，有时也引起局部倒装。也可不用倒装。

Many a time has Mike given me good advice.

Slowly and impressively he rose from his seat.

存在句（There be）

存在句的结构特征

存在句的结构模式是：