1、to be done完成式to have doneto have been done进行式to be doing-完成进行式to have been doing否定式否定词(not/never)+动词不定式考向一 不定式的作用1. 作主语:不定式作主语时,谓语用单数。往往用it 作形式主语,把不定式放在谓语后面。It took us two hours to finish the job.(1)其他系动词如look,appear等也可用于此句型。(2)当不定式作主语的句子中又有一个不定式作表语时,不能用It is .to.句型。试比较:It is to negate my own idea t
2、o believe him.(错)To believe him is to negate my own idea .(对) (3)It is+ adj. of / for sb to do sth结构中,当不定式的逻辑主语和前面的形容词可以构成系表结构时,用of,否则用 for。2. 作宾语(1)动词+不定式。He managed to escape from the fire.I find it hard to get along with him.(it 作形式宾语)(2)动词+疑问词+to,特殊疑问句+不定式相当于名词,作宾语。I dont know what to do next/ h
3、ow to do it next.不定式短语作宾语时,如果还带有宾语补足语,往往把不定式短语放在宾语补足语之后,用it 作形式宾语。I find it necessary to learn a foreign language.3. 作宾语补足语(1)动词+宾语+不定式(to do )。He warned me to be careful.注意:可以用动词不定式作宾补的动词有:ask,tell,order,want,get,would like,like,advise,invite,allow,help,wish,warn,expect,would prefer,encourage。(2)表见
4、解、看法的动词结构可为:动词+宾语+ to be 的不定式结构。We consider Tom to be one of the best students in our class.The book is believed to be useful.(被动语态)(3)There +不定式。We didnt expect there to be so many people there. 我们没料到会有那么多人在那里。有些动词需用 as 短语作补语,像regard,think,believe,take,consider。We regard Eric as our best teacher. 我
5、们认为艾瑞克是我们最好的老师。Mary took him as her father. 玛丽把他当作自己的父亲。学科*网(4)在动词feel (一感),hear, listen to(二听),have, let, make(三让),notice, see, watch, observe, look at(五看)(即:吾看三室两厅一感觉)等后面的补足语中,不定式不带to,但变为被动语态后,必须带to。They saw the boy fall off the tree.(5)help后面作宾语补足语的不定式可以带to,也可以不带to。I often help him (to) clean the
6、 room.I helped him (to) find his things.(2017新课标卷语法填空)Fat and salt are very important parts of a diet. They are required 63 (process) the food that we eat, to recover from injury and for several other bodily functions.【参考答案】to process4. 作定语不定式作定语,修饰名词或代词,不定式和它所修饰的名词之间有逻辑上的主谓关系、动状关系、同位关系或动宾关系。不定式通常要放
7、在这些被修饰的词后。I have a lot of work to do.(动宾关系)He is looking for a room to live in.(动状关系)He is the first person to think of the idea.(主谓关系)He has got a chance to go abroad.(同位关系)(1)不定式的逻辑主语是句子的主语时,不定式用主动形式表被动。Do you have anything else to say?(2)如果作定语的不定式是一个短语,则要保留不定式短语中的副词或介词。I need a pen to write with.
8、 (I will write with the pen ) 我需要一支钢笔写字。I have a little baby to look after. (I must look after the little baby ) 我有一个婴儿要照看。5. 作状语作状语,表示目的、结果、原因等,有时还有一些固定搭配的不定式短语,如in order to,so as to,so. as to,such.as to,enough to,too.to等。(1)作目的状语,just to,only to(仅仅为了),in order to,so as to,so(such). as to.(如此以便)He
9、ran so fast as to catch the first bus. 他飞快地跑以便赶上第一班车。(2)作结果状语,表事先没有预料到的,要放在句子后面。He hurried to the post office only to find it was closed.(3)作原因状语。We were very excited to hear the news.(4)作条件状语。To turn to the left, you could find a post office.6. 作表语不定式可放在be动词后面,构成表语。The question is how to put it int
10、o practice.(1)不定式在句中作表语时,对应的谓语动词用单数。(2)当主语是不定式时,表语不能用V-ing形式,可用不定式。To see is to believe. (眼见为实)(Seeing is believing. )1.(2017短文改错)When summer came(comes), they will invite their students pick the vegetables!【参考答案】 pick改为to pick2. (2017浙江卷语法填空)Sixteen years earlier (early), Pahlsson had removed the d
11、iamond ring 61 (cook) a meal.【参考答案】to cook 【答案解析】考查动词不定式。一个句子不能出现双重谓语,所以此处要用不定式作目的状语。故填to cook。考向二 不定式的时态和语态1. 不定式的时态(1)现在时:有时与谓语动词表示的动作同时发生,有时发生在谓语动词的动作之后。He seems to know this. (2)完成时:表示的动作发生在谓语动词表示的动作之前。Im sorry to have given you so much trouble.He seems to have caught a cold.(3)进行时:表示动作正在进行,与谓语动
12、词表示的动作同时发生。He seems to be eating something.(4)完成进行时:表示动作从过去某个时间开始,一直延续到现在,并有可能持续下去。She is known to have been working on the problem for many years.2. 不定式的语态当不定式的逻辑主语是其动作的承受者时,就用被动式。He was seen to enter the hall. 考向三 省to 的动词不定式一、使役动词后省略to的情况在let, make, have等使役动词后用作宾语补足语的不定式必须省略to。如:My mother wouldnt
13、let me go to the film. 我妈妈不会让我去看电影的。I dont like milk, but mother made me drink it. 我不喜欢牛奶,可是母亲强迫我喝。 1. 当使役动词用于被动语态时,要补上在主动语态中省略的to(主要是指make,let和have很少用于被动语态)。2. force, oblige等虽然也表示2. force, oblige使,但它们后用作宾语补足语的不定式必须带to。He forced me to go with them. 他迫使我同他们一起去。The police obliged him to leave. 警方强迫他离开
14、。二、感官动词后省略to的情况在感觉动词后用作宾语补足语的不定式必须省略to。I watched her get into the car. 我看着她上了车。I saw the woman enter a bank. 我看见这个女人进了一家银行。We often hear her sing this song. 我们经常听到她唱这首歌。Did you notice her leave the house? 她离开屋子你注意到了吗?1. 这里所说的感觉动词主要包括see, hear, observe, notice, feel, watch等。但是它们用于被动语态时,其后的不定式必须带to。但是,用于以上句型的动词notice 和watch和通常不用于被动语态。2. 类似地,动词look at和listen to后用作宾语补足语的不定式也不带to。学科/网3. 若动词feel后用作宾语补足语的不定式为 to be,则要带 to(其他情况不带 to)。4. 若不定式为完成式,通常应带 to。三、动词help后省略to的情况在动词help后用作宾语或宾语补足语的不定式可以不带to。Can I help (to) carry this heavy box? 我可以帮忙扛这个重箱子吗?Mothe
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