初中to不定式的用法总结

　　在上述情况下，如果不定式较长，显得头重脚轻，则可由代词让作形式主语(形式主语it不可由that或this等其他代词代替)，而将不定式放到后面。如：

　　1.It made him extremely happy to get contact with his family in Taiwan since they separated more than 40 years ago.

　　2.John admitted that it is always difficult for him to be on time.

　　不定式结构所表示的动作是谁做的，即不定式的逻辑主语，通常可以通过for sb. to do sth. 结构表达：

　　1.It is quite important for us to read good books during a general review.

　　2.It is not difficult fot those talented students to pass the exam.

　　在某些形容词(如careless，clever，considerate，foolish，good，impolite，kind, naughty，nice，silly，stupid等)作表语时，不定式后可以加of来引导出其逻辑主语：

　　1.It is very kind of you to tell me the truth.

　　2.It is stupid of him to do such a silly thing.

　　2)不定式作宾语

　　不定式作宾语有两种：一种是及物动词后直接跟带to的不定式, 另一种是“及物动词+疑问词+带to的不定式。

　　及物动词+带to的不定式结构:

　　只能跟动词不定式的动词，常见的有: afford, agree, aim, appear, ask, believe, care，claim，decide demand, desire, determine, expect, fail, happen, hesitate, hope, intend, learn, long, manage, offer, pretend, promise, prepare, refuse, seek, swear, undertake，want, wish等。

　　1.He managed to solve the complicated problem.

　　2.The stranger offered to show me the way.

　　3.Mr. Smith undertook to build a new plant in South Africa.

　　动词+疑问代(副)词+不定式：

　　这类动词常见的有advise, decide, find out, forget, inquire, know, learn, see, regard, remember, teach, tell, understand, wonder等。常见的疑问代(副)词有: what, when, where, which, how, whether等。

　　1.He does not know when to start.

　　2.You can decide whether to continue or to stop.

　　3.I will show you how to deal with it.

　　有时，不定式可由it代替，而把不定式放到后面去。这可以用这一结构表达：动词(如find, think，consider，feel等)+it+ 形容词+不定式。

　　1.She considers it necessary to make friends with him.

　　2.We find it difficult to finish all the homework before 9 o’clock.

　　3)不定式做表语

　　一种情况为主语是不定式(表示条件);表语也是不定式(表示结果)：

　　1.To see is to believe.

　　2.To work means to earn a living.

　　另一种情况为主语是以aim，duty，hope, idea，job, plan，problem, purpose，thing，wish等名词为中心的短语，或以what引导的名词性从句，不定式表语对主语起补充说明作用：;例如：

　　1.His aim is to study abroad in the near future.

　　2.The most important thing is to negotiate with them about the price.

　　3.What I want to say is to forget all the unhappy experience.

　　4)不定式作定语

　　不定式结构作名词词组修饰语主要有三种类型：

　　第一种，被修饰的名词词组是不定式的逻辑宾语。例如：

　　1.There was really nothing to fear.

　　2.He gave me an interesting book to read.

　　如果不定式是不及物动词，后面就得加相应的介词。例如：

　　1.Mary needs a friend to play with.

　　2.That girl has nothing to worry about.

　　3.They have a strict teacher to listen to.

　　4.Although the film had been on for ten minutes, I still was not able to find a chair to sit on.

　　第二种，被修饰的名词词组是不定式的逻辑主语;例如：

　　1.Have you got a key to unlock the door?

　　2.The action to be taken is correct.

　　3.There is nothing to be gained by pretending.

　　第三种，被修饰的名词词组是不定式的同位结构。这类名词通常是表示企图、努力、倾向、目的、愿望、is算、能力、意向等意义的名词：ability, attempt, effort, impulse, inclination,wish等。例如：

　　1.Her daughter will make an even bigger effort to please her.

　　2.I have no wishto quarrel withyou.

　　3.Neither of them had any inclination to do business with Mary.