Unit1SectionⅣGrammarWriting课件（共48张PPT）课件人教版选修七.ppt

Section Ⅳ;动词不定式;一、概念 动词不定式由“to＋动词原形”构成。这里的to是不定式标志，没有词义。不定式具有名词、形容词或副词的某些语法功能，又有动词的时态和语态的特点及作用。;二、时态与语态;They seem to have known each other for a long time. 他们好像认识好长时间了。 They pretended to be working hard when the teacher came in. 老师进来时他们假装正在用功。 I wanted the letter to be typed at once. 我要这封信立刻打印出来。 I think its an honor to have been given a chance to speak at the meeting. 被给予机会在会上发言我感到荣幸。;[点津] 当不定式逻辑主语不是句子的主语时，就要在不定式前加上其逻辑主语，该逻辑主语通常由for或of引出。 Its easy for him to work out this math problem. 对他来说解出这道数学题很容易。 Its careless of you to make such a mistake. 出了这样的错误，你太粗心了。;三、??词不定式的否定形式 动词不定式的否定式是在不定式符号to前加not,不带 to的不定式则在动词前加not。 Zhang Ming asked me not to stay at home all day. 张明要我不要整天待在家里。 My mother let me not do it by myself. 妈妈让我不要独自做这件事。 四、动词不定式的句法功能 动词不定式在句中不能独立作谓语，但可以作主语、宾语、宾语补足语、定语、表语和状语等多种成分。;1．不定式作主语 不定式短语作主语时，句子的谓语动词用单数形式。若不定式结构比较复杂，往往用it作形式主语，真正的主语放在句子的后面。 To catch the 5：00 bus early in the morning is not a good idea. 赶早晨5点的公共汽车不是个好主意。 It is not a good idea to catch the 5：00 bus early in the morning. 赶早晨5点的公共汽车不是个好主意。; [点津]　在“It is＋形容词＋不定式复合结构”句型中，当其中的形容词用来说明不定式逻辑主语的性格特点时，要由of引出逻辑主语，不能用for。这类形容词主要有bold, brave, careful, careless, clever, considerate, cruel, foolish, honest, kind, nice, rude, stupid, silly, thoughtful, wise等。 It is very kind of you to help me. 你帮我真是太好了。;2．不定式作宾语 (1)下列动词的后面常跟不定式作宾语。 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 The driver failed to see the other car in time. 司机没能及时看见另一辆车。 He cant afford to buy the expensive car. 他买不起那辆昂贵的小汽车。;[点津]　常接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。 (2)常用句型“主语＋v.＋it＋adj./n.＋to do sth.”。其中，it为 形式宾语，to do ...为真正的宾语。能用于这一句型的动词有think, find, make, believe, consider, suppose, feel等。 I think it useful to learn a foreign language. 我认为学门外语很有用。;[考题印证1];3．不定式作表语 放于be, become,