1、高中英语必修三Unit 4动词不定式作状语和定语精讲一、动词不定式在句中作状语,主要用来修饰动词和形容词,也可用来修饰副词。在句中,不定式可作目的状语、原因状语、结果状语、条件状语等,可表示目的、原因及结果等。1.目的状语,置于句首或句末,置于句首时常表示强调。为加强语气,常与inorder或soas 组成短语。*A group of youngpeople got together to discuss this question.一群年轻人聚在一起讨论这个问题。*In order to helphim, we would do everything we can.为了帮助他,我们将尽我们所
2、能。【名师点津】不定式作目的状语(1)置于句首时只用todo / in order to do。如用于表示否定, in order 或so as不能省略,用in order not to do 或 so as not to do形式。*I walked quietlyso as not to disturb the baby.我安静地走路,以免打扰婴儿。(2)不定式作目的状语时,其动作通常迟于谓语动词的动作。*I said that toencourage him.我这么说是为了鼓励他。(3)不定式作目的状语可转换为so that / in order that 或 so.that .引导的目
3、的状语从句。*He worked veryhard to pass the exam.He worked so hardthat he could pass the exam.He worked hard sothat/in order that he could pass the exam.他非常努力以便能通过考试。2.结果状语,多见于“too.to”; “enough to.”; only to do(表示意料之外的结果的发生);so/such.as to(意为“如此以至于”)结构句中。* Im too tired todo well.我太累了做不好。*He is old enoughto
4、 go to school .他到上学的年龄了。*He rushed back,only to find the book missing.他冲了回来,却发现书不见了。* She is so proudas to look down upon others.她太骄傲了,看不起别人。3.原因状语,多见于“sb.+be+adj.+to do.”结构句中。*I was very sad tohear the news.听到这个消息我很难过。4.独立动词不定式多用作插入语,表示说话人的心理状态或对事情的看法。*Id like to stayhealthy, but to be honest, I on
5、ly eat food that tastes good.我想保持健康,但说实话,我只吃味道好的食物。【名师点津】现在分词与不定式作结果状语的区别(1)动词不定式作结果状语强调的是一种意想不到的结果。*Anxiously, shetook the dress out of the package and tried it on, only to find it didnt fit.(2)现在分词作结果状语强调的是一种顺承的,必然造成的结果。*His father passedaway, leaving him a little money.二、动词不定式用作定语1.名词前有first,last
6、, next, only等词以及最高级修饰时, 其后要用动词不定式。*She was the firstwoman to win the gold medal in the Olympic Games.她是第一个在奥运会中赢得金牌的女性。2.动词不定式作定语常放在名词或不定代词后面作后置定语,表示尚未发生的动作。*Let us give himsomething to eat.让我们给他一些吃的东西。*We have muchhomework to do tonight.今晚我们有很多作业要做。3.当名词与定语之间存在动宾关系时。*I usually have alot of meetings
7、 to attend.我通常有很多会议要参加。*She is a niceperson to work with.她是一个很好的合作伙伴。4.抽象名词attempt,ability, chance, desire, determination, decision, plan, way或不定代词something,nothing等后面常用不定式作后置定语。*But Janis Adkinshas the ability and desire to do useful work.但是詹尼斯阿德金斯有能力和愿望去做有用的工作。5.当名词与定语有同位关系时。*We got the orderto le
8、ave the city.我们接到了离开这个城市的命令。6.当名词与定语之间存在主谓关系时。*We must find aperson to do the job.我们必须找到一个人来做这项工作。*We need someoneto go and get a doctor.我们需要有人去请医生。【知识延伸】动词不定式作主语,表语和宾语1.不定式作主语,表示具体的某次动作。若不定式结构比较复杂,常用it作形式主语,真正的主语放在句子的后面。*To do morningexercises is useful for our health.做早操对我们的健康有益。*Its importantfor
9、us to learn English well.学好英语对我们来说很重要。2.不定式作表语,表示将来的情况,说明主语的内容。其主语常常是wish,idea, task, purpose, duty, job等表示意向、打算、计划的词。*His dream is tobe a doctor.他的梦想是成为一名医生。*My work is toclean the room every day.我的工作是每天打扫房间。3.不定式作宾语,常跟在某些动词后。不定式作宾语的动词的记忆口诀:决心学会选计划,拒绝答应想假装;主动设法愿希望,同意请求帮一帮;准备威胁易声称,渴望申请败踌躇。其对应的动词分别为:
10、decide/determine,learn, choose, plan,refuse, promise,want/attempt, pretend,offer, manage,expect/wish/hope,agree, ask/beg,help,prepare, threaten,tend, claim,desire/long,apply, fail, hesitate。4.若不定式结构比较复杂,通常用it 作形式宾语,真正的宾语放在句子的后面,该用法常见的动词有think,find, make, believe, consider, suppose, feel等。*He cant affordto buy the expensive car.他买不起那辆昂贵的汽车。*I think it usefulto learn a foreign language.我认为学习一门外语是有用的。*I feel it my dutyto say that you are wrong.我觉得我有责任说你错了。3
