1、To-infinitives as subjects and predicatives动词不定式作主语和表语动词不定式作主语和表语Objects of this periodIn this period,you will:1.discover and summarize the pragmatic features and functional meaning of infinitives as the predicative&subject;2.realize language output by correctly using the grammatical structure of in
2、finitives.动词不定式的概念动词不定式的形式变化动词不定式作主语动词不定式作表语目目 录录1234动词不定式动词不定式?1.动词不定式是动词的一种非谓语形式，不能在句中单独作谓语。2.动词不定式具有动词的性质，可以有自己的宾语和状语，构成动词不定式短语。3.动词不定式也具有非动词的性质，相当于一个n./adj./adv.可以在句中担任主语、宾语、宾语补足语、表语、定语和状语。4.动词不定式有形式的变化，即一般式、进行式、完成式和被动式。1.不定式的一般式(to+动词原形动词原形)动作通常与谓语表示的动作同时或几乎同时发生，或是在它之后发生。动词不定式的形式变化动词不定式的形式变化He
3、appears to be very happy.To catch the train,we d better hurry to the station by taxi.(同时发生同时发生)(to catch the train 发生在 hurry to the station 之后)2.不定式的进行式（to be+doing)表示正在进行或与谓语表示的动作同时发生的动作。It happened to be raining when I got there.我到达那里的时候，碰巧在下雨。3.不定式的完成式(to have+done)不定式的完成式表示的动作在谓语表示的动作之前发生。Im sor
4、ry to have lost your key.我很抱歉把你的钥匙弄丢了。4.不定式的完成进行式（to have been+doing)不定式的完成进行式表示的动作在谓语表示的动作之前发生并且一直持续，并且并且仍在进行。He was said to have been living in London for twenty years.据说他在伦敦一直住了20年。5.不定式的被动语态被动语态当不定式逻辑上的主语是这个不定式表示的动作的承受者时，不定式一般要用被动形式。不定式的被动形式根据其与谓语动作发生的先后关系，有一般式和完成式两种。(1)一般式(to be done)These are
5、the books to be given out to the students.这些是要发给学生的书。(2)完成式(to have been done)The novel is said to have been translated into many languages.据说这部小说已被译成多种语言类别类别主动语态主动语态被动语态被动语态一般式一般式完成式完成式进行式进行式完成进行式完成进行式to doto be doneto have doneto have been doneto be doingto have been doing-观察下列句子，注意黑体部分在句中所作的句子成分。
6、1.However,during this period,it can be easy for some of them to form bad habits.2.To prevent harmful habits like these from dominating a teenager s life is essential.3.To change bad habits is never easy,even with many attempts.4.When to hold the sports meeting has not been decided.动词不定式作主语动词不定式作主语【语
7、法感悟】在句1中，it是，代替后面的动词不定式短语。在句2、3中，To prevent.和To change.都是动词不定式短语作。在句4中，When to hold.是“疑问词+to do”结构，该部分在句中作。形式形式主语主语 主语主语 主语主语 动词不定式具有名词特征，可以在句子中充当主语动词不定式具有名词特征，可以在句子中充当主语。（做主语时谓语动词用单数形式单数形式）To see_ to believe.眼见为实。To say _ one thing and to do is another.注：单个不定式作主语时，谓语用单数形式；两个及以上不定式作注：单个不定式作主语时，谓语用单数
8、形式；两个及以上不定式作主语时，谓语用复数形式；但作为一个整体时，谓语用单数形式。主语时，谓语用复数形式；但作为一个整体时，谓语用单数形式。Where to go on a holiday and when to go for the holiday _ not been decided.Where and when to go on a holiday _ not been decided.isishavehas动词不定式句子的主语时可以用形式主语动词不定式句子的主语时可以用形式主语it代替，将不定式置于句代替，将不定式置于句末，平衡句子结构。末，平衡句子结构。It is a shame t
9、o litter.乱扔垃圾可耻It is a privilege to meet you.认识你很荣幸it 作为形式主语时，常见句型。It+be+adj+(for sb)to do sth (adj 修饰物）修饰物）It+be+adj+(of sb)to do sth (adj 修饰人）修饰人）It+be+n.+to do sth It takes/took/will take sb some time/money to do sth 1.我们为后代保护地球是有必要。_ 2.你帮助我学英语真是太好了。_3.乘坐宇宙飞船飞往月球一定有趣。_4.中国人花了很长时间探索太空。_5.我们完成这项工作需
10、要一周多的时间。_TranslationIt is necessary for us to protect the earth for the future generations.It is very kind of you to help with my English.It must be great fun to fly to the moon in a spaceship.It took the Chinese a long time to explore the space.It will take us more than one week to finish the job.动
11、词不定式句子的主语时动词不定式句子的主语时,若其后面需要用动词作表语时，则作表语若其后面需要用动词作表语时，则作表语的动词也最好使用不定式形式，保持形式一致的动词也最好使用不定式形式，保持形式一致（to do is to do)To save me is to save yourself.救我也是救你自己。眼见为实。_动词不定式作句子的主语时动词不定式作句子的主语时,会有时态、语态的变化。会有时态、语态的变化。It is a great honor for me to be invited here today.To prepare this lesson takes a lot of tim
12、e but I find it worthwhile.To live with a tiger in a boat is dangerous.It is good to help others.To see is to believe.单句填空1.It takes about fifteen minutes(go)from my home to the school by bike.2.It is very kind of you(help)me with my spoken English.3.As students,it is necessary for us(learn)a second
13、 language.4.To form a good habit is difficult while(fall)into a bad habit is easy.5.When you are in trouble,it is helpful(turn)to your teacher.to go to help to learn to fall to turn.同义句转换1.The boy is too young to know what he should do when in trouble.The boy is too young to know when in trouble.2.F
14、or you,to lock the car when you do not use it is necessary.It s necessary the car when you do not use it.3.It was unforgivable to have made the same mistake twice.the same mistake twice was unforgivable.4.In a trial,a judge must decide which eyewitnesses he can believe.In a trial,a judge must decide
15、 .5.To make up for the lost time seems impossible.to make up for the lost time.what to do for you to lock To have made which eyewitnesses to believe It seems impossible.完成句子1.On school days,it is a habit for me (步行)from my home to the school.2.It is not polite (插话)when others are speaking.3.It is di
16、fficult for us (完成)writing the composition in a quarter of an hour.4.(改变)bad habits is never easy,even with many attempts.5.As far as I am concerned,it is no use (告诉他)not to worry.to walk to break in to finish To change telling him 观察下列句子，注意黑体部分在句中所作的句子成分。1.The purpose of the exchange program is to
17、promote the understanding between the two countries.2.During the Middle Ages,the purpose of Western art was to teach people about Christianity.3.The sports meeting which is to take place this Friday has been put off because of the heavy rain these days.动词不定式作表语动词不定式作表语4.Perhaps the best way to under
18、stand Western art is to look at the development of Western painting over the centuries.【语法感悟】在句1，2，3中，动词不定式作。在句4中，to understand.作，to look at.作。表语表语 定语定语 表语表语 1.动词不定式做表语直接用在系动词之后，起解释说明的作用，其主语通常是 suggestion,advice,proposal,aim,goal,purpose,plan,ambition,idea,intention,way,dream,duty,task,wish,hope等表示意
19、向、打算、计划的词。Her wish is to be a teacher.The duty of soldiers is to defend their country.2.动词不定式做表语直接用在动词不定式做表语直接用在 seem,appear,remain,prove,turn out 等之后，如：等之后，如：Several problems remain to be settled.3.以以What引导的主语从句，常用不定式作表语，说明主引导的主语从句，常用不定式作表语，说明主语的内容。语的内容。What I suggest is to ask your friends and tea
20、chers for help.What he wants is to solve the problem.What matters/counts most is to concentrate on your favourite things.4.用于表达想法，约定，义务，命令，可能性，命运等。如：用于表达想法，约定，义务，命令，可能性，命运等。如：We are to meet at the station at there.(表约定）How are we to convince him?（表可能性）You are to come when I call.（表命令）6.当当All 或或what引
21、导的主语从句中有实义动词引导的主语从句中有实义动词 do（以及（以及do的其他形的其他形式时，式时，作表语的不定式通常要省略作表语的不定式通常要省略to,即即“前有前有do,后无后无to”The question is how to carry out the plan.5.“疑问词疑问词+不定式不定式”也可以用作表语也可以用作表语All you should do now is devote yourself to studying hard.你现在应该做的事就是投入到刻苦的学习当中。注意：注意：动词不定式作表语时，在结构上是主动的，但在意动词不定式作表语时，在结构上是主动的，但在意义上却是
22、被动的。义上却是被动的。She is to blame.她应该收到责备。The house is to rent.此房出租。.单句填空1.The important thing is (finish)the work on time.2.The engine just won t start.Something seems (go)wrong with it.3.The purpose of new technology is to make life easier,not (make)it more difficult.4.The easiest way to accomplish this
23、 is (make)sure you conduct yourself as a good neighbour should.5.What I would suggest is (put)off the meeting.to finish to have gone to make to make to put.同义句转换1.The next step is that you should make sure that you know exactly what is required.The next step is that you know exactly what is required
24、.2.To develop a fine personality in children is the purpose of education.The purpose of education is a fine personality in children.3.You should be rewarded when you make a contribution to our country.You are when you make a contribution to our country.4.You must be patient and persistent if you wan
25、t to succeed.You must be patient and persistent if you are .to make sure to develop to be rewarded to succeed Exercises 1.His dream is _.他的梦想时有一天成为一名伟大的足球运动员3.Her work is _(work)in the nursing home everyday.4.It is necessary for everyone_.每个人都有必要为未来的生活做计划。5.It is important for everyone_.学习并掌握一些实用的技能
26、对每个人而言都是很重要的。to make plans for the futureto workto be a great football playerto master some practical skillsWork in pairs.Make conversations using the following questions and sentence patterns.What s your biggest dream/ambition in life?How are you going to make your dream come true?How are you going
27、 to achieve your goal?What is your plan?What might be difficult for you?How are you going to deal with that difficulty?My biggest dream/ambition in life is to .I think all I have to do is .My plan is to .I think one of the hardest things might be .I guess the best way to .I Have A DreamHello,everyon
28、e!Today Im here to share with you my dream.My biggest dream in life is to .People might wonder why I had such a special dream.Well,its because _.I really want to realize this dream.I think all I have to do is _.To realize my goal,my plan is to _.To be honest,I do understand it is never easy to pursu
29、e a dream.One of the hardest things might be _.However,nothing is impossible to a willing heart.Difficult as it is,I guess the best way to _ is _.I am proud of my dream,and I will definitely fight for it!Thank you for listening.Homework1.Finish Ex.1 and Ex.2 in Using Structures(P62 Workbook)2.Finish Ex.3 in Using Structures(P62 Workbook)Th-ank You
