infinitive 不定式

infinitive不定式不定式在句中可作除谓语以外的一切成份：主、表、宾、定、状、（主、宾）补语。

不定式作主语To say something is one thing, to do it is another.It is not fair to blame them for the accident. （it 形式主语）不定式作表语My suggestion is to carry out the plan immediately.The question is how to organize the work. （不定式的特殊结构，见后）不定式作宾语He offered to go with us.I don't know where to get the books.（不定式的特殊结构，见后）常跟 to do(不定式) 作宾语的 v:afford, agree, arrange, ask, attempt, beg, care, choose, claim （声称）,dare, decide, decline（谢绝）,desire, determine, fail, intend, learn, long, mean, offer, pretend, promise, refuse, seek, tend, undertake（承担）, volunteer.不定式的特殊结构构成：疑问代词、副词及 whether / if + to do常跟疑问代词、副词及 whether / if + to do作宾语的 v.有ask, consider, decide, discover, discuss, explain, find out, inquire, forget, know, learn, remember, show（演示）,tell, think, understand, wonder.ExamplesI still don’t know whom to turn to for help.They are trying to find out how to solve the problem.Show me where to put the books.They haven’t decide d yet (as to) whether to accept our offer of help.如果不定式作宾语又跟有补语，通常要用“it”作形式宾语，而将不定式放到补语后面去。

eg. 他们发现提前做好一切准备是不可能的。

They found it impossible to get everything ready in advance.I consider it my duty to point out their shortcomings.作宾 / 主语补足语Mr. Smith wants his son to become a lawyer.The suspected man was seen to enter the building.跟不带“to”的不定式作宾补的 v:see, hear, look at, listen to, feel, observe, watch, notice 等感官 v 及 let, make, have, keep.The teacher makes us write a composition every week.. （被动语态中要加上“to”）不定式的复合谓语结构复合谓语结构:（两个或多个部分构成复合谓语，如:He can do it）(1) be said (reported, known, believed, announced, claimed, stated,…) + to do=>It is said ... that …Beijing is known to have rich cultural heritage.(It is known that Beijing has ...)(2) seem（happen, appear, prove, tend）+ to doI happened to be out when she called.(3) be likely（certain, sure, willing, anxious, ready, bound,eager, reluctant) +to doThey are likely to succeed.She is always ready to help others.不定式作定语通常为后置修饰语:（post-modifier）He used to have a lot of meetings to attend.There is nothing to worry about.不定式作状语:目的状语He hurried through his work so as to（in order to）catch the train. They will go to the station to meet the guests.To survive the severe competition in the future society, one must have all-round abilities.不定式作状语:结果状语She was so angry as to be unable to speak.I hurried to Prof. Wang's house only to find he was out.（常表示令人不快的结果）不定式作状语:原因状语We are overjoyed to see you.I am happy to be here.I feel honored to give a speech here.作插入语插入语（独立成份）To be fair, he has worked hard these days.We don't like his idea, to tell you the truth.He is not good at English, to say nothing of French. (let alone French)逻辑主语(1) :用 of +n./ pron 来表示逻辑主语:当“be + adj. + 逻辑主语 + to do”结构中的 adj. 是absurd, bold, brave, careful, careless, clever, cruel, foolish, honest, kind, nice, polite, rude, silly, thoughtful, considerate, wise, wrong, typical, naughty, selfish, generous等表示人的品行的词Examples1. It is thoughtful of you to come to see me.2. I think it wrong of him not to accept our invitation.3. It is selfish of Tom not to lend his book to Mary.4. It is generous of you to help me with my work.逻辑主语(2) :用 for + n./ pron 表示逻辑主语:1. It is necessary for the goods to be packed in strong cases.2. I found it impossible for him to do the job alone.3. He gave me the phone number in order for me to contact him when we are in need of help.（他给了我他的电话号码,以便我们需要帮助时与他联系.）独立结构独立结构：（不定式的逻辑主语与句子主语不同）该结构在句中一般作说明情况的状语。

The plan was that the contending parties should reach an early agreement on basic principles, the details to be worked out later.(这个计划是让争执的双方先在基本原则上达成协议，细节以后再磋商。

)Another ExampleHe proposed a picnic, he himself to pay the railway tickets, and John to provide the food.不带“to”的不定式使用不带“to”的不定式的几种句型(1) 口语中，以why开头的简单问句Why do it that way? 为什么用这种方法来做这事呢？Why not go out for a walk? 为什么不出去散散步呢？(2) 在had better, would rather... (than)..., would ... rather than, would sooner ... (than), can not but..., can't help but..., may (might) as well... (不妨...)等习惯用法中ExamplesSince she is angry, we had better let her alone.Rather than beg in the street, he would prefer to die of hunger. (He would rather die of hunger than beg in the street...)I couldn't help but wait for the next bus to come.(3) 在do nothing/anything/everything but (except) 结构中Last night I did nothing but watch TV.John will do anything but work on a farm.但谓语动词不是do时，but / except所跟的不定式仍须带“to”The doctor told him nothing but to stop smoking.There was nothing for them to do but to remain silent.I have no choice/alternative/option but to give in to her power. 不定式的特殊用法一些固定结构中不定式的用法too ... to 表否定含义,而enough ... to ... 表肯定a. It was too cold for us to go shopping.(= It was so cold that we couldn't...)b. It was cold enough to freeze our fingers.但enough to 之前如有否定词，不定式也表否定含义The water isn't warm enough for us to go swimming.(=The water isn't warm enough so we can't...)(all too), only too等与不定式连用表示肯定意义He‘s only too pleased to help us. 非常愿意/高兴帮助我们。