以下是©无忧考网为大家整理的大学英语四级语法精要：情态动词(共含6篇），希望对您有所帮助。同时，但愿您也能像本文投稿人“cosmos”一样，积极向本站投稿分享好文章。
can’t, couldn’t表示否定的推测:
She can’t be serious.
A more suitable book can’t be found. (It is not possible to find a more suitable book.)
He couldn’t (can’t) be over fifty.
情态动词后接进行式, 完成式和完成进行式:
a) 情态动词可以和动词的进行式构成谓语, 表示”应该正在…”, “想必正在…”这类意思:
Why should we be sitting here doing nothing?
This isn’t what I ought to be doing.
She might still be thinking about the question you raised.
They must (may) be waiting for us, let’s hurry up.
They can’t be using the room now.
b) 情态动词有时和动词的完成形式构成谓语, 表示”应当已经…”, “想必已经…”这类意思:
I should have thought of that.
They shouldn’t have left so soon.
She must have arrived by now.
You needn’t have told them that.
Where can (could) he have gone?
He can’t have finished the work so soon.
He may not have achieved all his aims. But his effort is praise-
worthy.
We ought to have give you more help.
c) 情态动词间或也可以和一个动词的完成进行式构成谓语,表示”应当一直在…”, “想必一直在…”这类意思:
They are sweating all over. They must have been working in the fields.
They may have been discussing the problem this morning.
You should have been waiting for us. Why haven’t you?
She couldn’t have been swimming all day.
should, ought to: 表示应该做的事, ought to比should口气稍重一些.
You should (ought to) do as he says.
You shouldn’t (oughtn’t to) talk like that.
但这两者间也有一些差别, 在表示责任, 义务等该做的事情时, 常用ought to, 在表示某件事宜于做时, 多用should, 在下面的句子中这两个词就不宜换用:
You are his father. You ought to take care of him.
We should not use too many big words in our everyday speech.
动词
只能用动名词作宾语的动词: suggest, finish, avoid, stop, can’t help, mind, admit, enjoy, leave off, require, postpone, put off, delay, practise, fancy, excuse, pardon, advise, consider, deny, endure, escape, miss
既可用动名词, 也可用不定式作宾语的动词: love, like, hate, dislike, begin, start, continue, intend, attempt, can’t bear, propose, want, need, remember, forget, regret, neglect, try, deserve, can’t afford等.
有时两种结构之间意义差别不大, 有时却有不同的意思. 在remember, regret, want, try等词后差别是比较明显的.
i remember seeing her once somewhere.
i must remember to take my notebooks with me.
i regret not having accepted your advice.
i regret to say i haven’t given you enough help.
she doesn’t want (need) to come.
the house wants (needs) cleaning.
we must try to get everything done in time.
let’s try doing the work some other way.
悬垂修饰: 分词作状语时, 表示的必须是主语的一个动作或状态.
walking through the park, we saw a lot of flowers. (walking是we的动作, 正确)
walking through the park, the flowers looked very beautiful. (错误)
standing on the tower, we could see the whole city. (正确)
standing on the tower, the whole village could be seen. (错误)
Ⅴ 连词
并列连词
表示意义的引申: and, both…and, not only…but(also), as well as, and …as well, neither…nor
表示选择: or, either…or
表示转折: but, while, whereas, yet, however/nevertheless(也可认为是副词)
表示因果: for, so, therefore, hence
从属连词
表示时间: when, while, as, after, before, since, until(till), as soon as, once
表示原因: because, as, since, now that, seeing that
表示条件: if, unless, in case, provided(that), suppose, as long as, on condition (that),
表示其他关系: (al)though, than, as/so…as, lest, in order that, so…that
分词
意义: 过去分词通常来自及物动词, 带有被动意义和完成意义; 而现在分词有的来自及物动词, 有的来自不及物动词, 通常带有主动意义和未完成意义.
frozen food a freezing wind
a bored traveller a boring journey
a lost cause a losing battle
a conquered army a conquering army
a finished article the last finishing touch
the spoken word a speaking bird
a closed shop the closing hour
a recorded talk a recording machine
来自不及物动词的过去分词很少能单独用作前置修饰语, 能作这样用的仅限于下面几个词, 仅表示完成意义, 不表示被动意义.
the risen sun, fallen leaves, faded/withered flowers, returned students, retired workers, departed friends, escaped prisoners, the vanished jewels, newly-arrived visitors
用作后置修饰语的过去分词一般都带有修饰语或其他成分, 在意义上相当于关系分句.
Most of the people invited to the reception were old friends.
