高中英语选修七知识点总结

Unit2:不定式

不定式的被动形式

当不定式与逻辑主语之间是被动关系时 即不定式的逻辑主语是不定式所表示动作的承受者不定式一般要用被动形式。其被动式可以分为两种一般式和完成式。

(1) 一般式to be done表示不定式动作在谓语动词之后或者同时发生。

It is a great honor to be invited to speak 很荣幸被邀请在这里讲话。

The novel is said to be published next 据说这本小说下月要出版。

(2) 完成式 to have been done 表示不定式动作发生在谓语动词之前。

The book is said to have been translated into six

这本书据说已经被翻译成六种语言。

The boss preferred to have been given more work to

老板宁愿被分给更多的工作做。

被动 一般式 to be done 完成式 to have been done

不定式被动形式的作用

(1)作主语

It's an honor to be invited to the

很荣幸被邀请赴宴。

It's a pity to be kept in the house in such fine

在这样好的天气被关在家里真是遗憾。

(2)作表语

The letter is to be sent by 这封信笺要空邮。

(3) 作宾语

She didn't like to be treated as a

她不喜欢被当成孩子。

The boy asked to be given an opportunity to try

那男孩要求给他再试一次的机会。

(4)作宾语补足语

I'd like my bedroom to be 我想整理一下我的卧室。

(5)作定语

He was the last one to be asked to speak at the

他是最后一个在会上被邀请发言的人。

(6)作状语

His mother left the small village never to be seen

他母亲离开了那个小山村，再也没有人见过她。

不定式有些要注意的地方

(1) 感官动词和一些使役动词的不定式的主动形式要省去to但在变成被动语态后需要加上to能这样用的动词或动词词组有make have let see hear notice listen to watch等。

如：We often see him act like He is often seen to act like 我们常常看到他那样做。

(2)在can't help buthave nothing to do but结构中介词but后的不定式省去to。

如：I can't_help_but suspect his 我不禁怀疑起他的动机。

I have nothing to do but watch 我没什么事情可做除了看电视。

(3)不定式有时要用主动形式表示被动意义

①形容词以及含有形容词的名词后的不定式，一般用主动形式表示被动意义 其中形容词常见的有easy difficult important impossible等。

如：The work is impossible to finish in two 工作不可能两天之内完成。

English is not so easy to 英语并不好学。

① 一些固定用法 如“挨骂 受责备 受批评” 用be to blame “(东西等)出租”用to let。

V-ing 的用法：

作主语

Swimming is good for

作表语 Teaching is 教学相长.

注意：1)动名词和不定式都可以作主语，动名词作主语表示一般或抽象的多次性行为，不定式作主语往往表示具体的或一次性的动作。

如：

Playing with fire is (泛指玩火)

To play with fire will be (指一具体动作)

2). V-ing形式和不定式都要有对称性;当主语是不定式时，表语也用不定式;反之，当主语是 V-ing 形式时，表语也用 V-ing 形式。

To see is to Seeing is

3). It’s no use (good) doing sth

It’s a waste of time doing sth

it 作形式主语, 只用V-ing,不用不定式。

※ It is + + (for sb ) to do sth

It is no use crying over spilt 覆水难收。

It is a waste of time talking (talk) to him .

It is important for me to learn (learn) English .

作宾语 V-ing 形式既可作动词的宾语, 也可作介词的宾语。

We would appreciate hearing from 我们会珍惜你的来信。

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