动词不定式用法一、动词不定式的基本形式“不定式符号to+动词原形”，有时可以不带to。
动词不定式没有人称和数的变化。
在句中不能单独作谓语，但仍保留动词的特性，可以有自己的宾语、状语等。
动词不定式同它的宾语和状语一起构成不定式短语。
例如：to sell flowers in the street 在街上卖花to speak in the classroom 在教室里讲话二、动词不定式的语法功能动词不定式具有名词、形容词和副词的特征，可以作句子的主语、表语、宾语、宾语补足语、定语和状语（一）、作主语：动词不定式作主语可位于句首。
例如：To learn a skill is very important for everyone in today's society.也可使用it作形式主语，而将其置于句末。
例如：It is necessary for young students to learn a foreign language.动词不定式作主语的常用句型有：1. It is＋adj./ n. (＋for sb.／sth.) ＋to do sth.用于此句型的形容词有：easy, hard, difficult, possible, important, impossible, necessary, good, bad, exciting, interesting, surprising等。
例如：It is interesting to play this game.It is necessary for you to change your job.It was impossible for them to complete the task in such a short time.考例1：Is ____ possible to fly to the moon in a spaceship?A. nowB. manC. thatD. it用于此句型的名词有：pity, shame, pleasure, one’s duty, one’s&sb’job, fun, joy, good manners, bad manners等。
例如：What a pity it is for you to have missed such a wonderful film.It is good manners for the young to give their seats to the old.2. It is＋adj.＋of sb.＋to do sth.该句型中只能使用描述某人的品德、特征的形容词，如：kind, nice, wise, silly, polite, impolite, friendly, foolish, clever等。
例如：How rude it was of the boy to jump the queue!It is friendly of the family to try to make me feel at home in their house.How silly it was of you to give up such a good chance!3. It takes sb.＋some time＋to do sth. 该句型意为“做某事花费某人多长时间”。
例如：It took us half an hour to ride to the town by bike.而在下列结构中常用动名词做主语: It is no good/no use/ no help doing sth.练一练：对于一个人来说(For one )尽知一切是困难的。
爱与被爱是一个人所能寻找(seek)的最大幸福。
怎样消灭老鼠（rats）和苍蝇(flies)是一个大问题建造一所房子需要（requires）很多钱（二）、作表语动词不定式作表语常用于以下结构：My wi sh/ job/ aim/ goal is…及The next step/ measure is …等。
例如：Your job is to type the papers in the office.The next measure is to stop the river from being polluted.另外，be to do可表示将来计划好安排好的事情，可表示上级对下级的吩咐，要求，命令，也可以表示命中注定要发生的事情。
例如：You are to die at eighty-two. （上天安排。
）One is to struggle for one’s living. （自然安排）You are to be back by ten o’clock. （吩咐）Nobody is to say such a thing. （禁令）If you are to study in Europe, you must learn about a foreign language.（三）、作宾语常见的只能使用动词不定式作宾语的动词有：agree, choose, decide, hope, fail, wish, refuse, expect, manage, plan, intend, pretend, promise, offer, afford, demand, arrange等。
例如：They decided to build a highway between these two cities.She offered to help me when I was in trouble.believe, think, consider, feel, make等动词可用于“动词+ it +adj. / n+to do sth.”句型，其中使用it作形式宾语，而将真正的宾语动词不定式置于句末。
（发感信想让喜好厌恶之动词）例如：I think it necessary for us to have a good rest after the long work.She felt it her duty to help the old woman.注意：1）介词后面常跟动名词做宾语，动词不定式一般不做介词宾语，但是在but, except, besides, than, instead of, about, save后面可以做介词宾语。
例如：He is about to leave the city.We saw no alternative but/except/save to fight.Nothing remains but to wait and see.2）动名词也可以做宾语他们之间的区别在于：不定式表具体，动名词表一般。
试比较：I don’t like to play basketball today. I don’t like playing basketball.3）有些动词跟不定式和跟动名词表示的时间不一样，如regret, remember, forget。
跟不定式表示没有做过的事情；而跟动名词则表示做过的事情。
例如：I regret to tell you that you are dismissed.I remember meeting him somewhere before.Don’t forget to take your umbrella in case it rains.有些动词跟不定式和动名词表示的意思不同。
如stop, mean, try等。
例如：After a long walk, he stopped to have a rest.They stopped talking as soon as the teacher came in.I didn’t mean to hurt you.The heavy rain means our staying one more day here.Why not try taking a boat to give yourself a change.I tried to persuade him but failed.4）在动词want, need, require的后面一般跟不定式做宾语，跟单个的动名词则是主动表被动,如果带有的修饰成分较长也可以用不定式的被动式。
例如：He wants to see you and tell you something important.The watch needs mending since it can’t w ork properly.精品文档（四）、作宾补可后接动词不定式作宾补的动词有：advise, allow, ask, hear, order, see, tell, want, wish, watch等。
例如：The doctor advised her no to eat too much sugar.I wish you to go to the meeting with me.believe, consider, count, declare, deny, feel, find, guess, imagine, judge, know, prove, realize, suppose, think等动词后可接to be型不定式作宾补。
例如：He declared himself to be a college student. 他自称是名大学生。
The police proved him to be a thief. 警察局证实他是小偷。
hope, demand, suggest等动词不能后接动词不定式作宾补。
例如：【误】I hope my son to be back soon.【正】I hope my son will be back soon.【误】She suggests us to have a discussion about it.【正】She advises us to have a discussion about it.【正】She suggests that we (should) have a discussion about it.在主动结构中，下列动词后作宾补的动词不定式应省略to：“五看”(see, watch, notice, observe, look at)“三使”(make, let, have)“两听”(hear, listen to)“一感觉”(feel)。