blogger - 2008-10-3 16:56:00
一 定义： A 动词不定式的构成就是在to后面加动词原形：to do；动词不定式有各种时态和语态：
例句：
1 to do
I planned to study law in America.
His parents expect him to study abroad.
2 to be doing
He pretended to be listening to his teacher carefully.
He is said to be reading a book in that room now.
3 to have done
He is supposed to have finished this job.
The policemen were reported to have rescued the boy from the fire.
4 to be done
He wanted the letter to be typed at once.
She hates to be threatened by anybody.5 to have been done
He was very glad to have been invited to the party.
The book is said to have been published. B 否定动词不定式是在to 前面加 not: not to do. C 动词不定式的复合形式是在 to 的前面加上 how, what, where, when, which, why, whom, whether。I don’t know how to answer this question.
The problem is where to find the missing dog.
When to start hasn’t been decided yet. D 动词不定式除了不能直接做谓语外 (可以与连系动词一起作系表结构)，能做句中任何成分。二 不同功能：A 做主语：
To adapt is to survive. To see is to believe. To find a good job is the dream of every graduate.注意：
1 如果动词不定式作主语时太长，谓语太短，我们可以用it作形式主语，而把真正的主语放到后面。 OK: To finish this difficult job in just one hour is impossible.
Better: It is impossible to finish this difficult job in just one hour.
2 False: It is important of us to remember these new English words.
Right: It is important for us to remember these new English words.
因为我们不可以说：we are important. False: It is kind for you to help me lift this heavy box to the third floor.
Right: It is kind of you to help me lift this heavy box to the third floor.
因为我们可以说：you are kind.B 做宾语: I have decided to do this business as my priority. By 2005, this firm hopes to have opened another branch in America. I don’t know how to find this address under the darkness.
注意：
如果动词不定式作宾语太长，我们可以用it作形式宾语，而把真正的宾语放在后面。 Bad: I found to work with him difficult.
Good: I found it difficult to work with him.
Bad: I thought to repair this machine by himself impossible for him.
Good: I thought it impossible for him to repair this machine by himself.
C 做宾语补足语和主语补足语:I asked him to help me repair the broken machine.
宾语 宾语补足语 He was askedto help me repair the broken machine.
主语 主语补足语 We expected him to accept our offer.
He was expected to accept our offer.
注意：1 使役动词make, let, have 和感官动词see, watch, feel, hear, notice后面的动词不定式作
宾语补足语时不带to。但变成被动语态让动词不定式作主语补足语时要加to.I made my dog walk quickly.
My dog was made to walk quickly.
She saw him sneak out of the classroom.
He was seen to sneak out of the classroom.
2 动词find, help后面接动词不定式时可以带to, 也可以省略to.Right: I found him play football on the playground.
Right: I found him to play football on the playground.
Right: He was found to play football on the playground.
Right: I helped him repair the machine.
Right: I helped him to repair the machine.
Right: He was helped to repair the machine.
３ 除了１，２项中提到的动词以外的动词，无论主动语态或被动语态，都要带to. D 做表语:My job is to show you how to understand the authentic English grammar. It appeared to be a very good result.He seems to have known John before.To be a good government official is to serve every taxpayer wholeheartedly.To topple Saddam Housie and control Iraq is to gain a strategic way to control the whole world, because oil is the industry blood. 注意:动词不定式和进行时都可以表示将要发生的动作。The bus is to come soon.
The bus is coming.
He said that the train was to come soon.
He said that the train was coming.
E 做定语:I have something to do tomorrow.
动词不定式修饰 somethingI wanted these articles to be translated tonight by the secretary.
动词不定式修饰 articles
He was the first person to appear on the beach.
动词不定式修饰 personF 做状语:1 表示目的：
He is studying hardto pass the exam.
作目的状语；有时为了强调可用in order to或so as to He is studying hard in order to pass the exam.
He is studying hard so as to pass the exam.2 表示结果：常用so…as to, too…to, enough to的结构。He is studying so hard asto pass the exam.
He is too young to stay at home by himself.
She is old enoughto take care of herself.3 表示原因：通常情况下，我们用be + adjective + to do来表达人的心理活动和思想感情。I am sorry to hear that bad news.
She is happy to help the old lady to carry the heavy box.