转载：考研英语语法总结（四）——非谓语动词、情态动词

五、非谓语动词的其他考点

       1.接不定式或动名词做宾语都可以，但在意思上有区别的动词的用法

mean to do想要(做某事)                           propose to do 打算(做某事)

mean doing意味(做某事)                           propose doing建议(做某事)

forget to do忘记(要做的事)                       remember to do记得(要做某事)

forget doing忘记(已做的事)                      remember doing记得(已做过的事)

go on to do继而(做另一件事)                    stop to do停下来去做另一件事

go on doing继续(做原来的事)                   stop doing停止正在做的事

regret to do(对将要做的事)遗憾                regret doing(对已做过的事)后悔

如：

Mr. Jankin regretted having blamed his secretary for the mistake, for he later discovered it was his own fault.

The boy is constantly being told not to scratch the paint off the wall, but he goes on doing it all the same.

 2.不定式的习惯用法

句型：cannot help but do                   cannot but do

cannot choose but do                can do nothing but do

have no choice/alternative but to do

上述句型的意思接近，即“不得不做”、“不禁做”、“不由自主地做”、“不能不做”、“只能做”。其共同的特点是都有一个否定词和but。如：

Nobody can help but be fascinated by the world into which he is taken by the science fiction.When I consider how talented he is as a painter, I cannot help but believe that the public will appreciate his gift.

 3.动名词的习惯用法

句型：be busy/active doing sth.                        have difficulty/trouble/problem doing sth.

It’s no good/use/picnic doing sth.            have a good/great/wonderful time doing sth.

spend/waste time doing sth.                     There is no point/sense/harm/ use doing sth.

cannot help doing sth.                                   There is no doing sth.

I know it isn’t important but I can’t help thinking about it.

Alice was having trouble controlling the children because there were so many of them.

There is no use crying over spilt milk.

 4.there be 非谓语动词的用法

(1)做宾语时取决于谓语动词的持续要求。如：

The students expected there to be more reviewing classes before the final exams.

(expect要求接不定式做宾语)

(2)做目的状语或程度状语时用for there to be，做其他状语用there being。如：

For there to be successful communication, there must be attentiveness and involvement in the discussion itself by all present.

(for there to be…在句中做目的状语)

It isn’t cold enough for there to be a frost tonight, so I can leave Jim’s car out quite safely.

(for there to be…在句中做程度状语)

There being no further questions, we’ll stop here today.

(there being…做原因状语)

(3)引导主语用for there to be。如：

It is unusual for there to be no late comers today.

(4)做除for外的介词宾语，用there being。如：

He would always ignore the fact of there being such a contradiction in his inner thought.

六、情态动词

注意情态动词完成式的用法有两方面的含义：

 1.表示已经发生的情况

(1)must have +过去分词，表示对已发生情况的肯定推测，译为“(昨天)一定……”。如：

My pain must have been apparent the moment I walked into the room, for the first man I met asked sympathetically: “Are you feeling all right?”

(2)cant/couldn’t have +过去分词，表示对已发生情况的否定推测，译为“(昨天)一定没……”。 如：

Mary couldn’t have received my letter; otherwise she would have replied before now.

(3)may/might have +过去分词，表示对已发生的事情做不肯定、可能性很小的推测，或事实上根本没发生，译为“也许……”。如：

At Florida Power’s Crystal River plant, a potentially serious leakage of radioactive water may have been unknowingly caused by an electrician.

 2.表示虚拟语气

(1)needn’t have+过去分词，表示做了不必做的事，译为“其实没必要……”。如：

As it turned out to be a small house party, we needn’t have dressed up so formally.

(2)should /should not have +过去分词，表示应该做某事但实际上未做，或本不应该做但实际上做了, 译为“本(不)应该……”。如：

I regret having left the work unfinished; I should have planned everything ahead carefully.

(3)ought to have+过去分词，表示动作按理该发生了，但实际上未发生，译为“该……”，与should的完成式含义类似。如：

The porter ought to have called the fire-brigade as soon as he saw the fire in the stock, which went up in smoke.

(4)could have+过去分词，表示过去本来可以做但却未做，译为“完全可以……”。如：

What you said is right, but you could have phrased it more tactfully.

(5)may/might have + 过去分词，表示过去可以做但实际未做，译为“(那样)也许会……”。如：

It might have been better to include more punchy statistics and photos of equipment in the introduction to further assist first-time office automation managers.

 3.几个情态动词常考的句型

(1)may/might (just) as well“不妨，最好”，与had better相近。如：

Since the flight was cancelled, you might as well go by train.

(2)cannot/can’t…too… “越……越好，怎么也不过分”。注意这个句型的变体cannot…over…。如：

You cannot be too careful when you drive a car.

The final chapter covers organizational change and development. This subject cannot be overemphasized.

(3)usedn’t或didn’t use to为used to (do)的否定式。

(4)should 除了“应该”一层意思外，考研大纲还规定要掌握其“竟然”的意思。如：

I didn’t expect that he should have behaved like that.