英语专业4级考试语法之不定式.ppt

英语专业4级考试语法突破之,Infinitive,不定式,不定式的基本形式 不定式的基本形式为to do,根据动作发生的时间不同可以采用不同的形式，比如to be doing(正在发生)或to have dong(已经发生)或to have been doing(一直在发生)。不定式也有被动形式to be done或to have been done。不定式也有否定式，无论是何种时态语态的不定式，否定词not都应置于标志词to之前。,不定式的逻辑主语 不定式的逻辑主语一般由介词for引导，但表示人的性格行为特征的形容词作表语时，不定式的逻辑主语则由of引导，这样的形容词有: absurd,bold,brave,courageous,careful, careless,clever,wise,foolish,silly, stupid,good,nice,kind,thoughtful, considerate,greedy,generous,honest, modest,polite,rude,cruel,selfish,lazy, wicked e.g：It was very brave of you to save the drowning girl.,不定式在一些动词之后做宾语 这样的动词有：afford,arrange,attempt,claim,desire, determine,expect,fail,guarantee, endeavor,intend,pledge,pretend,resolve, request,swear,tend,venture e.g:Maybe we can arrange to go some other time.,不定式在一些结构中作主语补足语 不定式在以下结构中作主语补足语： be said/reported/thought/believed/known/ supposed+to do sth.注意不定式表示的动作发生的时间，并采用相应形式，比如to have done. e.g This strategy is reported to have been effective.,不定式作状语 不定式可以做目的状语，等同于in order to,so as to结构，注意so as to不能置于句首。不定式也可以用于soas to,suchas to,enoughto,tooto结构做程度状语。 不定式作结果状语只能出现在句子的末尾，一般表示不好的结果，有时用only加强语气。 e.g Many reporters hurried to the airport, only to be told that the superstar had already left.,不定式作定语时需要特别注意的问题 需要特别注意的是，如果动词为不及物动词，后面必须有相应的介词与前面所修饰的名词相呼应。 e.g He is looking for a room to live in. Smith is a good man to work with.,特殊的不定式结构 注意比较特殊的不定式结构，比如not/never tooto,toonot to,but/only tooto,too ready/eager/apt/inclined to等表示肯定意义。 e.g I am only too pleased to hear from you father.,表示“不得不做”的相关习惯用法 注意部分带to,部分不带to cannot help but do cannot but do cannot choose but do can do nothing but do have no choice/alternative but to do,There be 非谓语动词的用法 （1）作宾语时取决于谓语动词的持续要求 e.g The students expected there to be more reviewing classes before the final exams. （2）引导主语用for there to be e.g It is unusual for there to be no late comers today. （3）作除for外的介词宾语，用there being e.g He would always ignore the fact of there being such a contradiction in his inner thought.,（4）作目的状语或程度状语时用for there to be,作其他状语用there being e.g For there to be successful communication,there must be attentiveness and involvement in the discussion itself by all present. It isnt cold enough for there to be