牛津上海版英语九上.pptx

unit 2 great minds名词后的不定式动词不定式用在名词后 示例：The manager has announced his decision to retire early.英语的动词不定式可直接用在名词之后。动词不定式用于名词之后有两点要注意：1.有些名词，像wish,offer,decision后面可跟动词不定式。因为这些名词的动词形式与它们有关联，形式也一致或相似。He offered to catch the ball.He made an offer to catch the ball.2.动词不定式跟在名词后面常用来表达要对某事物做什么或将产生什么影响。Have you got a key to unlock this door?在上句中，key是动词不定式的主语：The key unlocks the door。不定式作主语一、不定式等非谓语形式作主语时，谓语动词一路走来都是单数身份；不少作主语的不定式与动名词在意义上相同。To see is to believe.=Seeing is believing.眼见为实。二、口语中，当作主语的不定式过长时，it不惜屈居有名无实的形式主语，常为平衡关系而挺身而出、替主出征，真主角反无官一身轻，悠哉断后。如：To learn a foreign language well is not easy.Its not easy to learn a foreign language well.要把一门外语学好不容易。留言提醒：在实际操作中，不定式（短语）还有权招聘一个逻辑主语，并由of/for出面料理-Its+adj.+for/of sb.+to do sth.，下例中的for me即是：Its hard for me to finish the task in such a short time.对我而言，要在如此短的时间里完成任务是困难的。聘of还是for？点击作表语的形容词属性可知：若形容词描述的是人的特征与品行，能修饰人（像kind，nice，good，clever，right，polite，careless等），则of适宜；如果形容的是事物的特点或外观等（如easy，hard/difficult，safe，interesting，important，necessary之类），则for主动上！下例正误可略见一斑：留言提醒：检验形容词描绘的是不是人的特征与品行、能否修饰人-sb.be adj.可助上一臂之力。三、一个都不能少：还有几种耳熟能详的不定式作主语句式。如：1.It takes/took/will take(sb.)some time to do sth.如：It takes(us)hours to do our homework every day.我们每天要花上数小时做家庭作业2.Its+n.+to do sth.如：Its a mistake for us not to help him.我们不帮他是个错误。留言提醒：要对不定式否定，暗号照旧-not在不定式前面加！3.It cost/costs sb.some time/money to do sth.如：It cost me ten yuan to buy this bag.我花了十元钱买这个书包。不定式作表语1、表示目的。The next step is to make sure that you know exactly what is required.下一步你要真正弄清楚需要的是什么。2、表示事态发展的结果、预期的结果、不幸的命运或语言。He was to perish in a shipwreck and to l-eave a wife and two children.后来他在一次船只失事中死了，留下了妻子和两个孩子。3、用于第一人称疑问句，表示征求意见。What am I to say if they ask me the question?要是他们问我这个问题，我该怎么回答呢？4、用于被动语态，相当于can/could,should,ought to,must,具有情态意义。You are to be rewarded.你应该受到奖励。（should）Its nowhere to be found.哪儿也找不到它。（cant be)These books are not to be sold.这些书不应该卖掉。（ought not to be)5、表示“同意、安排、命令、决定、劝告、意愿、禁止”等。They are to marry next week.他们将在下周结婚。（安排）Children are not to smoke.儿童不准吸烟。（禁止）You must be patient and persistent if you are to succeed.想要成功，就必须有耐心，有毅力。（愿望）6、不定式作表语，可用主动形式表示被动意义。She is to blame.她应该受到责备。不定式作宾语不定式作宾语1)动词+不定式afford aim appear agree arrange ask be decide bother care choose come dare demand desire determine expect elect endeavor hope fail happen help hesitate learn long mean manage offer ought plan prepare pretend promise refuse seem tend wait wish undertake举例：The driver failed to see the other car in time.司机没能及时看见另一辆车。I happen to know the answer to your question.我碰巧知道你那道问题的答案。动词不定式和疑问词连用不定式可以和疑问代词who,what,which及疑问副词when,how,where等连用，构成不定式短语，在句子中作主语、宾语、表语等。现将这种用法归纳如下。一、“疑问词动词不定式”结构有两种形式：1.“疑问词to动词原形”I dont know what to say.我不知道说什么。Can you tell me how to make a paper boat？你能告诉我怎样做一只纸船吗？2.“疑问词名词to动词原形”I dont know which topic to choose.我不知道选哪个题目。