The Infinitive 不定式

不定式的构成 肯定式：to do 否定式：not to do

不定式可根据时态和语态有不同的形式 to do/to be done to be doing to have done/to have been done

不定式在句子中可做的成分 主语，宾语，表语，定语，状语，补语

做主语 To know oneself is difficult. To hesitate means failure. To learn English well is important. To travel around the world is my dream. Not to see him this time is a pity.

被动式 To be invited to the party is my honor. To have been given a second chance made him happy. To be loved is a kind of happiness.

常用“it”做形式主语,句型如下： It is adj./n.+ (for/of sb) to do sth It is difficult to know oneself . It means failure to hesitate. It is important to learn English well. It is my dream to travel around the world. It is a pity not to see him this time.

特殊句型： It takes sb some time to do sth. It takes sth to do sth. It took me ten hours to finish the work. It takes courage to say sorry first.

作表语（表具体，表将来） 常用来做主语的名词： dream, ambition, resolution, plan, wish, job, duty 常用来做主语的从句： What I can/should/have to do… All that I can/should/have to do…

Her ambition is to become an actress. My dream is to visit Paris one day. His duty is to defend his country. Their plan is to take a long vacation. Tom’s wish is to fly to the moon some day.

Our job today is to clean up the house. My ambition is to be admitted to Peking University. What I can do is (to) wait. All (that) she has to do is (to) tell the truth. The only thing we could do was (to) find a part-time job.

当主语和表语皆为不定式或动名词时，要保持二者形式的一致。 To talk to her is to talk to a wall. To see is to believe. To help others is to help ourselves. Talking to her is talking to a wall. Seeing is believing. Helping others is helping ourselves.

BE TO DO STH be to do 表示:预定或预计做某事；应该、必须、注定会做某事。表将来。 We are to hold an art exhibition next month. He is to become a great man. Everyone is to do something for our class.

特殊句型 Sb /sth be to blame (for sth). I think she is to blame. The traffic jam was to blame. Tom rather than I ____________ (该负责) for the loss. is to blame

不定式作表语表将来；动名词作表语表概念，习惯，或经常发生的动作。 My job is teaching English, but today my job is to babysit my little nephew. My hobby is collecting stamps.

作宾语：V.+to do sth 有些动词后要求跟不定式作宾语: expect, decide, happen, refuse, tend, fail, manage 有些要求跟动名词作宾语: finish, mind, appreciate, imagine,

有些动词后两种都可以跟，但意思不同，请注意。 Remember to do sth Remember doing sth Forget to do sth Forget doing sth Stop to do sth Stop doing sth

Regret to do sth Regret doing sth Can’t help to do sth Can’t help doing sth Mean to do sth. Mean doing sth.

Seem to do… Seem to be doing… Seem to have done… appear/pretend/happen也跟这三种形式的不定式作宾语。 I happen to go there. I happen to be reading the book. I happen to have read the book.

做宾补: V+ sb (to) do sth 要带to 的： ask/tell/warn/persuade sb to do sth; encourage sb to do sth; inspire sb to do sth; expect sb to do sth

注意下列几个词的用法 allow/permit/forbid/advise sb to do sth allow/permit/forbid/advise doing sth suggest sb’s /sb doing sth

不带to的不定式做宾补 1.使役动词：make, let, have 即：make/let/have sb do sth make 可以由被动结构，在被动结构中，要还原to,即： be made to do sth. 而let, have 不用于被动结构

The boss makes the children work 10 hours a day. The children are made to work 10 hours a day. Let us go in. I will have a worker repair your car.

2.感官类动词后也要求跟不带to的不定式，切变被动结构时也要还原to. hear/see/notice/watch sb do sth be seen/heard/noticed to do sth I saw him go out . He was seen to go out.

区分以下几种形式的宾补 see sb doing sth see sb do sth see sb/sth done make sb do sth. make sb done ( make oneself heard/understood/noticed)

主补 be made/seen to do sth be told /asked to do sth 句型： Sb. be said / reported / known /believed to do to be doing to have done

作定语 与所修饰的名词之间有三种关系： 1. 主动关系： He is not a man to bow before difficulties. Is Tom a man to keep his word? He is always the first to arrive and the last to leave.

2.动宾关系(句子中有不定式动作的逻辑主语，这一点很关键。） I have lots of things to do. Let’s find a comfortable place to live in. I have a family to support. Is he a man to depend on（for me) ?

Compare Do you have any clothes to wash? Do you have any clothes to be washed? Do you have any clothes to be washed (by me) ?

There is nothing to do (for us). There is nothing to eat. There are a lot of cars _________ (choose) from. I don’t have a pen ____________ with. to choose to write 句型： There is no need (for sb) to do sth

Thanks for giving me a chance to go abroad. 3.同位关系，即说明其修饰名词的内容 Thanks for giving me a chance to go abroad. Is this a way to save time? He has the ability to communicate with others. I have a dream to become a doctor.

Remember 当名词前有序数词，最高级，the only/ very/last修饰时，用不定式。 He is the only man to survive. He is the very one to help us. He is the best one to be fit for the job.

做状语 1.目的状语（可位于句首或句尾） To save the child, he lost his own life. He worked hard to pass the exams. I’ve come here to see you.

in order to & so as to In order to 可在句首或句尾；而so as to 只能在句尾。 He worked hard in order to/so as to pass the exams. In order to pass the exams, he worked hard . In order not to fail in the exams, he worked hard .

He is too young to go to school. He is not old enough to go to school. 2.结果状语 ① too… to…; …enough to do…; so…as to do… He is too young to go to school. He is not old enough to go to school. He isn’t so stupid as to believe him.

② (only) to do…表出乎意料的结果；而doing 表必然结果。 He hurried to the station, only to find the train had left. The man died, (only) leaving his son alone in the world.

③其它 His father lived to be 108 years old. What have I said to make you so angry? He left his wife never to return. He fell off his bike to break his leg.

3.原因状语 Sb be +adj. to do/have done… I’m pleased to meet you. I feel honored to go to the party. She is disappointed to see that. I’m sorry to have given you so much trouble.

They jumped with joy to hear the news. He burst into laughter to see his funny look. She fell into despair to know the truth .

复合谓语 1.sb/sth be+adj. +to do. 该句型的主语和不定式的动词之间有动宾关系，但不定时只用主动式。 The air is hard to breathe. He is easy to get along with.

2.Sb/sth be+ adj.+ to do sth be willing to do sth. be ready to do sth be anxious/eager to do sth be able/unable to do sth be bound to do sth be likely/unlikely to do sth be careful to do sth

插入语 To tell the truth To begin/start with To be honest To be frank To make things worse