八年级英语语法讲解.docx

1、八年级英语语法讲解动词1. 不定式定义:由to动词原形构成。2.用途：主动形式 被动形式一般式 （not) to make （not) to be made 疑问词不定式结构疑问词who,what,which,when,where,whether,how后可接不定式构成不定式短语，在句中作主语、宾语、表语等。如： When to leave for London has not been decided yet. （不定式在句子中做主语）Mr. Smith didnt know whether to leave or stay there. （不定式在句子中做宾语）I asked Profes

2、sor Xu how to learn English well. （不定式在句子中做间接宾语）The question was where to get the medicine needed. （不定式在句子中表语）以上例句中疑问词不定式部分，均可转换为相应的从句形式。如：When we shall leavehow I could learn 动词不定式的语法功能一、作主语动词不定式作主语时，句子的谓语动词常用单数，其位置有以下两种： (1)把不定式置于句首。如： To get there by bike will take us half an hour. (2)用it作形式主语，把真

3、正的主语不定式置于句后，常用于下列句式中。如： Itbe名词to do Its our duty to take good care of the old. 二、作宾语1) 动词+ 不定式 e.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 f

4、ailed 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。2）动词+不定式 ；动词+宾语+不定式ask, beg, choose, expect , hate, help intend like, love, need prefer, prepare, promise, want, wishI like to keep everything tidy.我喜欢每件东西都保持整洁。I like you to keep everything

5、tidy.我喜欢你使每件东西都保持整洁。I want to speak to Tom.我想和汤姆谈话。I want you to speak to Tom.我想让你和汤姆谈话。3） 动词+疑问词+ to decide, know, consider forget, learn, remember, show, understand, see, wonder, hear, find out, explain, tellPlease show us how to do that. 请演示给我们如何去做。There are so many kinds of tape-recorders on sal

6、e that I cant make up my mind which to buy.有这么多的录音机，我都拿不定主意买哪一种。注意:疑问词带不定式在句中作成分时，谓语动词用单数。The question is how to put it into practice. 问题是怎样把它付诸实施。四、作表语不定式作表语表示具体动作或将来动作；To be kind to the enemy is to be cruel to the people. 五、作状语1）目的状语To only to (仅仅为了),in order to,so as to,so(such) as to (如此以便)He ra

7、n so fast as to catch the first bus.他飞快地跑以便赶上第一班车。I come here only to say good-bye to you.我来仅仅是向你告别。2）作结果状语，表事先没有预料到的，要放在句子后面。What have I said to make you angry.He searched the room only to find nothing.3)表原因 Im glad to see you.六、作定语不定式作定语 不定式在句中作定语，置于被修饰的名词或代词之后。如： The next train to arrive is from

8、Washington. Have you anything to be taken to your sister? 省to 的动词不定式1） 情态动词 ( 除ought 外，ought to)：2） 使役动词 let, have, make：3） 感官动词 see, watch, look at, notice , observe, hear, listen to, smell, feel, find 等后作宾补，省略to。注意：在被动语态中则to 不能省掉。I saw him dance. =He was seen to dance.The boss made them work the w

9、hole night.=They were made to work the whole night.动词不定式的否定式Tell him not to shut the windowShe pretended not to see me when I passed by. 我走过的时候，她假装没看见。1、 Why not +动词原形表达向某人提出建议 为什么不? 干吗不?例如：Why not take a holiday? 干吗不去度假?2、Its for sb.和 Its of sb. 1）for sb. 常用于表示事物的特征特点，表示客观形式的形容词，如easy, hard, diffic

10、ult,interesting, impossible等：Its very hard for him to study two languages. 对他来说学两门外语是很难的。 2）of sb的句型一般用表示人物的性格，品德，表示主观感情或态度的形容词，如good, kind, nice, clever, foolish, right。Its very nice of you to help me. 你来帮助我，你真是太好了。4、不定式的特殊句型tooto 1）tooto太以至于He is too excited to speak. 他太激动了，说不出话来。5、部分动词后接不定式或动名词时，

11、意义差别较大，应根据句子语境选择使用。 forget,remember,regret后接不定式，表示现在或未来的动作，接动名词表示动作已经发生。如： 动名词与不定式语义不同的有1、stop to dostop doing2、 forget to doforget doing 3、remember to doremember doing4、 regret to doregret doing 5 、try to dotry doing 6、go on to dogo on doing7、afraid to doafraid doing 8、interested to dointerested do

12、ing例题 1、 forget doing/to doforget to do忘记要去做某事。(未做)forget doing忘记做过某事。(已做)2、stop doing/to dostop to do停止，中断做某事后去做另一件事。stop doing停止做某事。They stop to smoke a cigarette.他们停下来，抽了根烟。I must stop smoking.我必须戒烟了。3、 remember doing/to doremember to do 记得去做某事(未做)remember doing记得做过某事(已做)Remember to go to the pos

13、t office after school.记着放学后去趟邮局。Dont you remember seeing the man before? 你不记得以前见过那个人吗?4、 regret doing/to doregret to do对要做的事遗憾。(未做)regret doing对做过的事遗憾、后悔。(已做)5、try doing/to dotry to do努力，企图做某事。try doing试验，试着做某事。You must try to be more careful. 你可要多加小心。I tried gardening but didnt succeed. 我试着种果木花卉，但未

14、成功。6、 go on doing/to dogo on to do做了一件事后，接着做另一件事。go on doing继续做原来做的事。After he had finished his maths，he went on to do his physics. 做完数学后，他接着去做物理。Go on doing the other exercise after you have finished this one.作完这个练习后，接着做其他的练习7、be afraid doing/to dobe afraid to do不敢，胆怯去做某事，是主观上的原因不去做，意为怕；be afraid of

15、 doing担心出现doing的状况、结果。 doing 是客观上造成的，意为生怕，恐怕She was afraid to step further in grass because she was afraid of being bitten by a snake.她生怕被蛇咬着，而不敢在草丛中再走一步。She was afraid to wake her husband. 她不敢去叫醒她丈夫。She was afraid of waking her husband. 她生怕吵醒她丈夫。8、 be interested doing/to dointerested to do对做某事感兴趣，想

16、了解某事。interested in doing对某种想法感兴趣，doing 通常为想法。I shall be interested to know what happens. 我很想知道发生了什么事。 (想了解)Im interested in working in Switzerland. Do you have any idea about that?我对在瑞士工作感兴趣。你想过这事吗?(一种想法)二、 现在完成时1.概念：过去发生或已经完成的动作对现在造成的影响或结果，或从过去已经开始，持续到现在的动作或状态。 2.时间状语：yet,already,just,never,ever,so

17、 far,by now,since+时间点，for+时间段，recently, lately, in the past few years, etc. 3.基本结构：have/has + done 4.否定形式：have/has + not +done. 5.一般疑问句：have或has。 6.例句：Ive written an article. The countryside has changed a lot in the past few years.三、 过去进行时1.概念：表示过去某段时间或某一时刻正在发生或进行的行为或动作。 2.时间状语：at this time yesterda

18、y, at that time或以when引导的谓语动词是一般过去时的时间状语等。 3.基本结构：was/were+doing 4.否定形式：was/were + not + doing. 5.一般疑问句：把was或were放于句首。 6.例句：At that time she was working in a PLA unit.When he came in, I was reading a newspaper.四、反意疑问句的用法详解反意疑问句是由两部分组成的，前一部分是对事物的陈述（即陈述句），后一部分是简短的提问（即简短疑问句），中间用逗号隔开。如果前一部分用肯定句，后一部分就用否定疑

19、问句；如果前一部分用否定句，后一部分就用肯定疑问句。两部分的人称和时态要一致。其回答是用yes或no来表示。 一、含be(is, are, was, were)动词的反意疑问句其句型是：句型1:主语+ be+其它，isnt( arent, wasnt, werent)+ 主语?句型2:主语+ be not+其它，is(are, was, were) + 主语? You are from America, arent you? Yes, I am. No, Im not. It isnt very cold today, is it? Yes, it is. No, it isnt. Tom w

20、as away yesterday, wasnt he? Yes, he was. No, he wasnt. The Green werent at home last night, were they? Yes, they were. No, they werent. Mary is reading English now, isnt she? Yes, she is. No, she isnt. Your parents arent going to have a party this Sunday, are they? Yes, they are. No, they arent. Th

21、e girls were singing when the teacher came in, werent they?Yes, they were. No, they werent.注意：There be句型 There is an old picture on the wall, isnt there?Yes, there is. No, there isnt. There arent any children in the room, are there?Yes, there are. No, there arent. There wasnt a telephone call for me

22、, was there?Yes, there was. No, there wasnt. There were enough people to pick apples, werent there?Yes, there were. No there werent. 二、行为动词的一般现在时的反意疑问句其句型是：句型1: 主语+动词原形+其它，dont I(you, we, they)?句型2: 主语+ dont+动词原形+其它，do I(you, we, they)?句型3: 主语+动词第三人称单数+其它，doesnt he(she, it)?句型4: 主语+ doesnt+动词原形+其它，d

23、oes he(she, it)? You often watch TV in the evening, dont you? Yes, I do. No, I dont. The students dont study hard, do they? Yes, they do. No, they dont. Mary studies Chinese hard, doesnt she? Yes, she does. No, she doesnt. The boy doesnt often go to school by bike, does he? Yes, he does. No, he does

24、nt. The first class begins at eight, doesnt it? Yes, it does. No, it doesnt.三、 行为动词的一般过去时的反意疑问句其句型是：句型1: 主语+动词过去式+其它，didnt+主语?句型2: 主语+didnt+动词原形+其它，did +主语? You watched TV last night, didnt you? Yes, I did. No, I didnt. Jims parents didnt go to Hong Kong last month, did they?Yes, they did. No, they

25、didnt. The rain stopped, didnt it? Yes, it did. No, it didnt. Mr. Clarke didnt buy a car, didnt he? Yes, he did. No, he didnt.四、一般将来时的反意疑问句 其句型是：句型1: 主语+will+动词原形+其它，wont+主语?句型2: 主语+ wont +动词原形+其它，will +主语? The boys will play games, wont they? Yes, they will. No, they wont. It wont stop raining, wil

26、l it? Yes, it will. No, it wont. Mr. Smith will visit our school next week, wont he? Yes, he will. No, he wont.注意：There be句型的一般将来时 There will be a basketball match tomorrow, wont there?Yes, there will. No, there wont. There wont be too much pollution in the future, will there?Yes, there will. No, th

27、ere wont.五、现在完成时的反意疑问句其句型是：句型1: 主语+have+动词过去分词+其它，havent+主语?句型2: 主语+ havent +动词过去分词+其它，have +主语?句型3: 主语+has+动词过去分词+其它，hasnt+主语?句型4: 主语+ hasnt +动词过去分词+其它，has +主语? You have been to Shanghai before, havent you? Yes I have. No, I havent. You havent been to Shanghai before, have you? Yes I have. No, I ha

28、vent. Jack has done his homework, hasnt he? Yes, he has. No, he hasnt. Jack hasnt done his homework, has he? Yes, he has. No, he hasnt.六、含有情态动词的反意疑问句其句型是：句型1: 主语+情态动词+动词原形+其它，情态动词否定形式+主语?句型2: 主语+情态动词否定形式+动词原形+其它，情态动词+主语? You can speak French, cant you? Yes, I can. No, I cant. They cant understand me

29、, can they? Yes, they can. No, they cant. Ann could swim when she was six, couldnt she? Yes, she could. No, she couldnt. The students must study hard, mustnt they? Yes, they must. No, they neednt.注意：You must go home now, neednt you? Yes, I must. No, I neednt. 值得注意的是有时英语的谓语动词并不用否定式（即没加上not），而是用上了“never, little, few, hardly, nothing, nobody”等词，这时该陈述句也属于否定句，因此，反意疑问句的后半部分应用肯定疑问式。 You have never been to Beijing, have you? Yes, I have. No, I havent. Mr. Fat has few friends here, does he? Yes, he does. No, he doesnt. There is little milk in the bottle