初中英语语法教案

语法教案第一天：一、今天我们首先来学英语里面最最基础的东西：英语的词类。这里我们先来看我们想象英语的一首语法歌谣。这首歌谣会贯穿于我们整个培训阶段，所以我们不仅要熟读而且每个人都要把它背下来。接下来我们先来看这首歌谣，这首歌谣主要有两部分（关于词类、关于三种句型）英语单词几十万，归根到底十类词名代数连介副，叹冠形动连介叹冠不变态代词数词小变态名动形副很变态动词当然最变态代词有主格宾格物主格数词有基数词和序数词连介叹冠不变态代词数词小变态名动形副很变态动词当然最变态名词有可数与不可数单数与复数比较最高形容与副词连介叹冠不变态代词数词小变态名动形副很变态动词当然最变态同一动作发生在不同时间，动词形式变态时态时态就是动词在不同时间状态下发生的变态一般现在时单三s、es，其它无变化一般过去时动词词尾+ed一般将来时will+原形一般过去将来时would+原形现在进行时am is are+动词ing过去进行时was were+动词ing现在完成时has have+ed过去完成时had+ed助动词就是帮助动词变态的词动词不仅有时态，而且还有语态表示什么被怎样要用被动式be+过去分词就是被动态动词一变永不变，be在前面变时态被动语态的时态就是be动词在不同时间下的大变态这里我们首先来讲讲代词和数词，连介叹冠不变态，我们就暂不讲了。代词数词小变态一、 代词：代词要记住人称代词主格宾格物主格，要想记住我们就要背表格主格Iyouhesheitweyouthey宾格meyouhimheritusyouthem形容词性物主格myyourhisheritsouryourtheir名词性物主格mineyourshishersitsoursyourstheirs反身代词myselfyourselfhimselfherselfitselfourselvesyourselvesthemselves二、关于代词的其他一些知识点及用法，我们这里就暂不讲了。接下来我们来看看数词，数词有基数词和序数词。下面我们来看看这份表格。编号基数序数1onefirst2twosecond3threethird4fourfourth5fivefifth6sixsixth7sevenseventh8eighteighth9nineninth10tententh11eleveneleventh12twelvetwelfth13thirteenthirteenth14fourteenfourteenth15fifteenfifteenth16sixteensixteenth17seventeenseventeenth18eighteeneighteenth19nineteennineteenth20twentytwentieth30thirtythirtieth40fortyfortieth50fiftyfiftieth60sixtysixtieth70seventyseventieth80eightyeightieth90ninetyninetiethNow we can make a conclusion：1、 基数词变序数词在其后加-th，发音为/2、 以y结尾的基数词构成序数词，y变i，再加-eth3、 不规则的序数词，如上表格中4、 序数词前通常要加定冠词the第二天：三、接下来我们来讲讲名词，名词主要是讲可数与不可数以及可数名词的单复数1、 名词分为可数名词和不可数名词，不可数名词通常指一些物质名词和抽象名词，如rice、water、health、progress、friendship、etc.这个主要靠我们平时的积累。2、 我们这里主要是讲可数名词的单数与复数及其变化规则：1） 首先我们来看看它们的规则变化，如下表格规则变化列表单数词尾构成方法单数复数一般辅音或元音字母+y加-sbookpendaybookspensdays词尾为s、x、sh、ch加-esbusboxwatchbrushbusesboxeswatchesbrushes词尾为辅音字母+o加-esherotomatoheroestomatoes词尾为元音字母+o及辅音字母+o的缩写词、外来词加-sradiophoto(graph)pianoradiosphotospianos词尾为辅音字母+y改y为I，再加-esfamilyfactoryfamiliesfactories词尾为f(fe)改f(fe)为v，再加-eslifeleafwifelivesleaveswives词尾为f的例外情况加-sroofchiefroofschiefs2） 接下来我们再来看看名词里的一些不规则变化，如下列表格 少数不规则名词的复数形式，如表一构成方法单数复数元 音 交 替a emanwomanmenwomeno efoottoothfeedteethou imousemice词尾加-en或-renoxchildoxenchildren单复同形fishdeersheepfishdeersheep 国家名称作为一个专有名词，表示“某国人（的），某国语言”的词常由其国家名称派生出来，如表二国家名（n.）该国人（n.）该国语言（n.）该国（人）的(adj.)ChinaJapanRussiaGermanyAmericaAustraliaCanadaEnglandFranceChineseJapaneseRussian(s)German(s)American(s)Australian(s)Canadian(s)Englishman(men)Frenchman(men)ChineseJapaneseRussianGermanEnglishEnglishEnglishEnglishFrenchChineseJapaneseRussianGermanAmericanAustralianCanadianEnglishFrench 复合名词的复数形式，如表三构成方法单数复数只把复合名词中的主体名词变成复数looker-on 旁观者son-in-law女婿lookers-onsons-in-law没有主体名词，在最后一个词后面加-sgrown-up 成年人go-between 中间人grown-upsgo-betweens复合名词的组成部分都变成复数形式man servantwoman doctormen servantswomen doctors四、名动形副很变态，动词当然最变态，那么接下来我们就先来讲讲形容词和副词，这里我们稍作讲解，之后我们来对它的使用及其它一些东西再作一个专题讲解。形容词、副词记住原级、比较级和最高级，原级无变化，比较级加-er，最高级加-est，特殊情况也要记：“好”“坏”“多”“少”“远”“老”1、 规则变化构成方法原级比较级最高级单音节词和少数双音节词一般在词尾加-er若-esthighcleverfastslowhigherclevererfasterslowerhighestcleverestfastestslowest以字母e结尾的词，加-r或-stlatesimplelatersimplerlatestsimplest重读闭音节词只有一个辅音字母时，应先双写辅音字母，再加-er或-estbigthinfatbiggerthinnerfatterbiggestthinnestfattest以“辅音字母+y”结尾的双音节词，先改“y”为“i“,再加-er或-esteasyhappyearlyeasierhappierearliereasiesthappiestearliest多音节词和部分双音节词在词前加more或mostdeliciousinterestingeasilyusefulmore deliciousmore interestingmore easilymore usefulmost deliciousmost interestingmost easilymost useful2、 不规则变化原级比较级最高级good/wellbad/badly/illmany/muchlittlefaroldbetterworsemorelessfarther（比较远的）/further（更进一步的）older(比较老的)/elder（年龄比较大的）bestworstmostleastfarthest（最远的）/furthest（程度最远的）oldest（最老的）/eldest（最年长的）五、动词，这是英语里最变态的词，下面就对它进行详细的讲解1、 动词的分类：按照动词的词义和在句中的作用，通常分为行为动词，即我们平时所说的实义动词，系动词，助动词和情态动词A 行为动词：表示动作或状态，能独立作谓语。它又为分及物动词和不及物动词a. 及物动词：它也有多种形式1） 后面跟一个宾语，如 I enjoyed the book very much.2） 后面跟双宾语，这类词有bring、buy、find、get、hand、leave、offer、teach、tell、write、etc.Jim will give us a talk on English manes.3） 后面跟宾补，它与跟双宾的区别我们将放在句子中讲解 带名词作宾补的动词有：call、leave、name、make、think、etc. 带形容词作宾补的动词有：cut、turn、prove、want、paint、keep、get、etc.Uncle Wang calls it “bike”.Youd better keep the windows open.b. 不及物动词：本身词义完整，后面不跟宾语，跟宾语时通常要再加一介词如：The sun rises up.其实不及物动词vi.+prep.=vt.我们来看看下面这些词组：动词和介词的搭配laugh at 嘲笑take part in 参加think of 想出go on with 继续worry about 为担心look after 照看、照料take care of 关心look at 看look like 看起来像look for 寻找listen to 听get to 到达wait for 等候play with 玩耍point at 指向point to 指着hear of 听说talk about 谈论think about 考虑come from 来自fall behind 落后agree with 同意、赞同arrive in 到达（大地方）arrive at 到达（小地方）catch up with 赶上、超过hear from 收到来信pay for 支付、付钱preferto喜欢不喜欢shout at 对呼喊knock at the door 敲门tieto 把系在get on with 与某人相处stopfrom阻止某人做某事move to 搬家至某地do well in 在方面做得好B 系动词：本身有词义，不能单独作谓语，必须和表语一起构成谓语，最常见的是be、look、get、feel、sound、become、keep、seem、turn、grow、remain、taste、smell、etc.注：连系动词后直接跟形容词作表语，不能用副词XThe stars look brightly in the dark sky. The stars look bright in the dark sky.C 助动词：本身无词义，不能单独作谓语，只能和主要动词一起构成谓语动词，表否定、疑问、时态、语态等语法形式，或用来加强语气。常见的助动词有be、do、have、shall、will、etc.1）be构成时态，主要是进行时态She is doing some shopping with her mother now.构成被动语态The basket was put in a car by the twins.与动词不定式构成谓语These books are not to be taken out of the room.2）have构成完成时态The twin brothers have not seen each other for ten years.和动词不定式构成谓语，表示客观环境促使不得不做的事have to/has toShe has to help her mother with the housework every day.3）do 构成疑问句和否定句Does he do his homework after school?用来加强语气I do want to buy a sweater like yours.用来代替动词词组Have you washed your shoes? Yes, I did yesterday.4）shall 构成将来时态，单纯表示未来情况，用于第一人称 We shall have a football match next week.5）will 构成将来时，用于各种人称 They will go to England for a holiday.6）had better+动词原形（最好），表示建议和劝告，否定形式had better not+动词原形Wed better look up the word in the dictionary.7）be able to 表示某一个动作被成功地完成，否定形式为be not able to He will come if he is able to.8）be going to 表示意欲、打算做某一件事情 We are going to Beijing tomorrow.D 情态动词：表示说话人对某一动作或状态的态度，或表示主观设想。本身有词义，但不能单独作谓语动词，必须和不带to的动词不定式（ought除外）连用，没有人称和数的变化。常用的情态动词有can、may、must、ought to、will、shall、should、would、need、dare，它们的用法及其它一些细节，我们以后再作专题讲，这里就这样导入。2、 接下来我们来看看这个最为变态的动词的各类变态A 加-s的规则：动词一般现在时单数第三人称形式的构成规则动词原形第三人称单数形式一般动词在词尾加-s（在清辅音后读/s/，在浊辅音或元音后读/z/）sleeptakewantfindlivestaysleepstakeswantsfindslivesstays以字母s、x、ch、sh、或o结尾的动词加-es，读/iz/；如动词词尾已有e，则只加-sdressfixwatchpushlosedodressesfixeswatchespusheslosesdoes以辅音字母+y结尾的动词，先变y为I，再加-es，读/z/flycrytrycarrystudyfliescriestriescarriesstudiesB 构成动词-ed形式的规则（过去式和过去分词）a. 规则动词的过去式和过去分词的构成是一样的，都加-ed构成规则动词原形变化后一般在动词原形末尾加-edlookstaycalllastpointsoundlookedstayedcalledlastedpointedsounded结尾有e的动词加-dlovehopelovedhoped结尾是“辅音字母+y”的动词，变“y”为“i”，再加-edstudytrystudiedtried末尾只有一个辅音字母的重读闭音节动词，先双写这个辅音字母，再加-edstepdropfitsteppeddroppedfittedb. 不规则动词的过去式及过去分词的形式是不规则的，分为六大类（备有资料可发放）1）原形、过去式、过去分词完全相同的动词（A-A-A型）2）过去式与过去分词相同的动词（A-B-B型）3）原形与过去分词相同的动词（A-B-A型）4）原形、过去式、过去分词的变化为i-a-u型的动词5）原形、过去式、过去分词最后一个字母为w-w-wn型的动词6）过去分词均以-en结尾的动词7）其它动词C 英语动词的现在分词，一般在动词末尾加-ing规则动词原形加-ing形式后一般在原形动词末尾加-ingdodrinkflydoingdrinkingflying以不发音字母e结尾的动词，先去掉e，再加-ingridehavetakeridinghavingtaking以重读闭音节结尾的动词，词末只有一个辅音字母，应先双写这一字母再加-ingstopsitputbeginstoppingsittingputtingbeginning以ie结尾的，先将ie变为y，再加-ingdielietiedyinglyingtying第三天：六、上面我们已经讲了英语里的各类词，也讲了最为变态的动词，接下来我们来讲时态，因为“时态时态就是动词在不同时间状态下的变态”。首先我们对时态先来个总体的概括，让我们大家了解一下英语里面的所有时态。其实学英语很简单，它的时态来来去去都是这几种，只不过句式与单词在轮回转变着。时态主要由四种时间和四种状态来组合构成16种时态，但我们中学里主要掌握它的八种主要时态。一般进行完成完成进行现在单三s、es，其它无变化am、is、are+inghas/have+ed/过去-edwas、were+inghad+ed/将来will+do/过去将来would+do/这里我来用work here的各种句式（肯、否、问、答）造句，并使用多种人称：1)I work here. I dont work here. Do you work here? Yes, I do. No, I dont.2)Mary works here. Mary doesnt work here. Does Mary work here? Yes, she does. No, she doesnt.3)I worked here. I didnt work here. Did you work here? Yes, I did. No, I didnt.4)I will work here. I wont work here. Will you work here? Yes, I will. No, I wont.5）I would work here. I wouldnt work here. Would you work here? Yes, I would. No, I would.6）I am working here now. I am not working here. Are you working here now? Yes, I am. No, Im not.7）I have worked here for a long time. I havent worked here for a long time. Have you worked here for a long time? Yes, I have. No, I havent.8）I was working here last March. I wasnt working here last March. Were you working here last March? Yes, I was. No, I wasnt.9）I had worked here by last summer. I hadnt worked here by last summer. Had you worked here by last summer? Yes, I had. No, I hadnt.第四、五天：七、接下来我们来看一些主要及常用的时态（八大时态）A 一般现在时一般现在时的使用场合可分两大类：一类是不受现在时间限制的场合；另一类是与现在时间相关的场合。学习这一时态除了掌握基本用法外，还应了解一些习惯用法。第一类：表述不受现在时间限制的自然现象以及自然界的各种状况：The sun rises in the east.Heat expands gas.Water boils at 100Oc.The earth runs around the sun.第二类：表述真理或道理，如某些格言、俗语等：Seeing is believing.Practice makes perfect.Where there is a will, there is a way.第三类：表述不受客观时间限制的客观事实：such as: The river flows into the East China Sea. The lake lies in the West of China. The West Lake lies in Hangzhou. Japan lies to the east of China.第四类：表述涉及现在时间（往往是一个界限模糊的时间范围）的惯常动作：for example: Mary always gets up at 6 oclock.I often go to work by bus.She practices oral English every morning.The teacher never takes a bus to the school.第四类因涉及惯常动作，所以往往与某些频度副词及表示惯常时间的状语联系在一起。频度副词按频度大小排列如下：always、often、usually、sometimes、seldom(接近全否定)、never(强语势的否定，频度显然为零)，此外，修饰惯常动作的词语还有every day，each day，every three days，in the morning，once a week等。如：He gets up at six in the morning. I go home once a week.第五类：某些表示现在时刻发生的动词（如例句所示）可以使用一般现在时，但此用法仅限于特定动词。如：I declare the meeting open. I say that the answer is wrong. I wish you a happy New Year. Please watch what I do. I turn on the recorder, press this button and it starts.第六类：状态动词在涉及现在时间时不取现在进行时形式，它们用一般现在时形式表示现在的状态。如：I want to tell you something important. I have a new car. You look very beautiful in the dress.(系表结构)The food tastes nice, doesnt it? (系表结构) What do you think about it? Sorry, I forget your phone number. I like music very much. I prefer to have tea after supper. The shoes dont fit me.状态动词是用来表示某种状态的实义动词，它们包括以下四类：第一类：表示拥有的动词：have、own、possess、 (have的含义应相当于own，其它含义不在此列)第二类：表示态度的动词：love、like、hate、prefer、etc.第三类：表示感官活动的动词：see、hear、smell、etc.第四类：表示某种心智状况的动词：want、forget、remember、think(作“认为”讲时)、believe、realize、etc.B 一般过去时是用来表示过去时间范围中的活动的一种时态，其中包括在过去一个时间点上发生的活动，也包括在过去一个时间段上发生的活动，还包括一些习惯用法。一般过去时的用法：第一类：表述发生在过去时间点上的动作。如：I saw him yesterday.He went to bed very early last night.She came to see us last week.Father gave me a new dictionary yesterday.第二类：表述发生在过去时间段上的动作，但侧重其延续的全过程，并暗示这一过程的终止。如：We lived in Shanghai for ten years.She slept for three hours last night.The talk lasted four hours.They stayed at home yesterday.第三类：表述过去的惯常动作，同一般现在时表示惯常动作一样，此用法多与频度词语相关。如：She often came to see me. Father smoked a lot three years ago. We went to school together when we were boys.第四类：表示过去连续发生的两个或几个动作，注意例句，用and这一连词的情况。如：He stood up and went out. He ate and listened to the radio. The teacher stepped into the office and sat down.第五类：在含有状语从句的复合句中表示两个过去发生的动作的时间关系、如：We went to the house when it began to rain. When I went into the room, I saw him sitting in a chair. As he walked, he sang.C 现在进行时与现在一段时间或现在时刻的活动相关，主要用于现在正进行的动作，学习者应注意所谓“现在进行”的不同情况，并注意某些习惯用法。此外，还应研究此时态与一般现在时的主要区别。现在进行时的用法：第一类：表述现在正在进行的活动，多用于延续动词，但有时也可用瞬间动词。如：I am writing a letter now.Is it raining hard?The boy is looking out of the window. 第二类：表述现在时间范围内有间断的延续活动。 如：She is working on a new book.I am studying French at the university.My father is writing a novel. 第三类：表示一种尚未完成的渐变过程。 如：It is getting warmer and warmer. The world is becoming smaller. We are realizing that the problem is serious. 第四类：与always等副词连用，表述说话人厌烦或认为超过限度的动作。 如：He is always asking the question.He is always thinking of the problem.He is constantly leaving his thing about.She is forever changing her clothes. 第五类：表述将要发生的动作，此用法限于某些表示位置移动的动词。 如：We are leaving for London tomorrow.They are starting tomorrow morning.I am meeting an important person this afternoon.D 表示现在进行的活动一般都暗示这一活动尚未完结，但当涉及瞬间动词时，则仅表示此时刻正在发生的活动，如：Look! She is putting up a new picture on the wall. 过去进行时的某些用法与现在进行时有相似之处，但也有某些习惯用法不尽相同。在学习过去进行时的时候，我们应注意在某些复合句中的时态配合问题，主句动词与从句动词在此种情况中具有各种不同类型的关系，我们要认真进行研究。过去进行时的用法：第一类：表示在过去某时刻正在进行的活动。如：I was reading at ten oclock last night.It was raining when I woke up.I was trying to look up the word when you came in.第二类：表示过去某段时间里有间断地延续的动作。如：He was working in Nanjing at that time. She was studying French then. They were building a new bridge.第三类：在复合句中使用过去进行时。如：He was reading while his wife was cooking. While he was driving, he was thinking about the matter.第四类：特定用法：过去进行进+when+一般过去时，表示“正进行忽然间发生另一动作“。如：I was walking down the street when it began to rain. They were talking about the boss when the boss came in.第五类：表示对过去某一时刻来说将要发生的动作，限于位置移动的动词。如：He was leaving a few days later. He was attending the meeting the next day. Mary was always complaining about the weather. She was constantly changing her mind.E 现在完成时是英语各种时态中比较难于掌握的一种时态形式。这一时态涉及到现在，但动作不一定发生在现在这一时刻，它往往与说话人及其所处情景有密切关联。对于一个发生在过去的动作，则使用现在完成时。因此，现在完成时不仅仅是表示“现在完成了“的一种意思。此外，我们还应在理解上述基本概念之后掌握在某些语句中的习惯用法。现在完成时的用法：第一类：表述过去发生的某动作对现在的影响（与说话人及情景直接相关）。如：I have seen him before.She has read the book.We have finished the work.第二类：表述过去开始延续到现在的动作。如：They have lived here for two years. She has stayed in bed for three days. You have kept the book for ten days.第三类：表述从过去到现在某动作总共发生的次数。如：He has been to London twice. He has done it many times. We have seen the man three times.第四类：表述从过去到现在某动作所涉及的总数量。如：We have learned 1,000 words. The writer has written three novels. You have had four cakes.第五类：（否定）表述从过去到现在没有发生的动作，此时可用for+一段时间。如：He hasnt cleaned the room for two days. They havent heard from him for two years. I havent written to him for years.第六类：在since的特定语句中使用现在完成时。如：I have lived in Shanghai since 1981. I have lived in Shanghai since I came to China. I have lived in Shanghai since I came to China three years ago.第七类：在现在完成的句子中某些副词（already、just、yet、never、ever）的用法；注意副词位置。如：We have already finished the work. We have finished the work already. We have just finished the work. We have not finished the work yet. We have never seen such a nice picture. Have you ever been to Shanghai?第八类：用现在完成时与特定语词结合表述说话人的态度情感。如：This is the best book I have ever read. I have never read such an interesting book. He is the cleverest boy I have ever met.第九类：涉及this is（第几次）的句型使用现在完成时。如：This is the third time that I have met him. This is the first time that I have visited your country.第十类：现在完成时与特定时间状语连用。如：I have covered 50 pages so far. You have made great progress in the past ten years. I have felt much better these days.1） 在现在完成时的否定句中，瞬间动词可与for+（一段时间）的状语连用，因为瞬间动词的否定情况是延续性质的。2） since句型中，since后接从句的动词一般用瞬间动词，用一般过去时，主句则用现在完成时。此外，在特定语境中，since句型的主句也可用过去完成时。F 涉及将来活动的表达形式第一类：用shall或will表示将来活动。如：It will be Monday tomorrow.He will be back soon.There will be a meeting next week.They will go to Shanghai next week (month、year).第二类：用will be doing形式表示将来活动，此类表示在将来某一时间正在进行的活动。如：He will be working in London during March. What will you be doing this time tomorrow. He will be waiting at the gate when you arrive there.第三类：用will be doing的形式客观地表示将来要发生的动作、活动等（注意在具体情景中区分第二、三类）。如：They will be arriving soon. I shall shortly be working as a teacher. How long will you be staying here for? I shall be attending the meeting.第四类：用will have done(即将来完成时)表示在将来某一时间已完成的活动，多与特定状语连用（见例句）。如：You will have finished (reading) it by the end of next month. Ill have finished my work by four this afternoon. We will have repaired the car before she comes back.1） 在现代英语中，用一般将来时（will、shall）表示将来活动往往带有一点情感色彩。2） 将来活动可以多种手段进行表达，不限于传统语法所涉及的一般将来时，下面我们即列举了其中重要的表达手段。第五类：用be going to do表达主语打算在将来某时进行的活动。如：What are you going to do today?How long are you going to stay here?We are going to have a meeting tomorrow.第六类：用be going to do表达将来某时很可能或注定要发生的事情。如：Hurry up! We are going to be late. It is going to rain. She is going to be fat.第七类：表示位置移动的动词以进行时形式表示将来发生的事情，这里我们稍做解析。如：They are leaving here on Sunday. She is going to Paris next week. We are moving to a new house this year. 这类词有：go、come、arrive、start、leave、take off（起飞）、move、etc.第八类：表示将来活动的其他手段。如：be to do(预定要)，be about to(行将)I am to attend a meeting this afternoon. They are to have a talk with us. She is about to leave. The train is about to start. The book is to be published in October.G涉及过去将来活动的表达形式一、 过去将来与一般将来时有着极其相似之处，只是过去将来时是指以过去某一时间为基点来看将来的活动。如：He said that he would call for me at seven.He told me that his sister would come the next day.She asked me whether I was going to attend the party.She wondered where she would go.We were about to leave when it rained.H过去完成时1、 过去完成时多用来表示两个过去动作的先后次序。如：He had left when we arrived. His father had died when he arrived at home.2、 过去完成时在特定时间状语的配合下表示截至过去某点已完成的动作。如：They had built a new house by the end of last year.The boy had been able to speak three languages by the time he was seven.3、过去完成时有时用于间接引语表示主句动作与从句动作的先后。如：He told me that he had read the article three days before. He said that they had left the day before.4、在间接引语中有特定的过去时间则不用过去完成时。如：He told me that he was born in 1960. The teacher said that the writer wrote the story in 1930.* have a practice第六天：八、情态动词：在我们中学阶段情态动词也是一个非常重要的知识点，这里我们来做个专题进行讲解。必要性可以运用情态动词表述，也可以运用特定句型表述。从实际表达出发，我们把“必须“务必”“不得不”“应当”等意思都包括在“必要性”的范畴之中。对必要性进行否定涉及“没有必要”和“务必不要”两类意思。A、必要性的表达手段：第一类：用must表达必要性。如：You must work hard at English. Must I stay here?第二类：用have to表达必要性。如：I have to stay here. You will have to go there with him. I had to wait for her. Does she have to go there?第三类：用ought to（应该）表达必要性。否定式则表示“不应该”，是对必要性的否定。如：You ought to work harder at chemistry. He ought to pay for that, oughtnt he? You oughtnt to tell him the news. You ought to have told him about it.第四类：用should（应该）表达必要性。意思与第三类大体相同。如：She should eat less. You should be working in the lab tonight. You shouldnt refer to the answer key. You shouldnt have referred to the answer key.第五类：表示“有必要”和“无需”的特定句型。注意need的用法。如：It is necessary to remember the words. There is great need to remember the rules. We need to repair the machine.（行为动词）We neednt repair the old machine.（情态动词）It is not necessary to remember the words.说明：1、mu