连词课件.doc

连词分为并列连词和从属连词两大类。并列连词是连接主语与主语，谓语与谓语，句子与句子，分词与分词的词，它要求前后两部分有相同的形式和语法作用；而从属连词一般连接主句与从句，从句形式有名词性从句，定语从句和状语从句等。并列连词及其用法1）表示意义引申的并列连词1. and的九大用法要点1. 连接两个相同的比较级，表示“越来越”。如：It moves faster and faster. 它动得越来越快。Your work is getting better and better. 你的工作干得越来越好了。2. 连接两个相同的动词，表示动作的反复或连续。如：He coughed and coughed. 他咳个不停。He tried and tried but without success. 他试了又试，但没有成功。3. 连接两个相同的名词，表示“许多”或“有各种各样的” (即有好的也有坏的)。如：They talked for hours and hours. 他们谈了很长时间。There are books and books. 有各种各样的书(即书有好坏之分)。4. 在口语中用在 come, go, run, stay, stop, try 等之后表示目的(and 在此相当于不定式符号 to)。如：Come and have a look. 来看一看。We will try and get one tomorrow. 我们明天设法弄一个来。We ought to stop and think. 我们应该停下来想一想。Will you go and fetch me some paper, please? 请你去给我拿点纸来好吗?以上动词除 try 只能用原形外，其它动词都可有多种形式。如：正：We stayed and had a drink with him. 我们留下来同他喝 了一杯。正：We stopped and bought some flowers. 我们停下来买了些 花。误：He tried and finished the work in time. 注：在 come, go 之后的 and 有时可以省略(尤其在美国英语中)。如：Ill come (and) see you later. 我晚些时候再来看你。5. 用在祈使句后，表示结果，意为“那么”(暗示一种条件)。如：Work hard and youll pass the examinations (=If you workhard, youll pass the examinations). 努力吧，你考试会及格的。Arrive late once more and youre fired (=If you arrivelate once more, youre fired). 再迟到一次，就把你开除。有时也可以不是用于祈使句后表示结果。如：One more step and I will fire. 你再动一步，我就要开枪了。6. 用在 good, nice, fine 等之后，表示“很”、“挺”。如：Its nice and cool under the tree. 这树下很凉快。The book is nice and expensive. 这本书很贵。7. 在主从复合句中，不要在主句前误加 and。如：要是下雨，我们就呆在家里。正：If it rains, well stay at home. 误：If it rains, and well stay at home. 8. 某些用 and 连接的两个词，与汉语顺序相反，不要按汉语词序颠倒过来。如：rich and poor 贫富 land and water 水陆right and left 左右 north and south 南北food and drink 饮食 food and clothing 衣食9. 比较以下各组句子有无连词 and 的差别：天气晴朗，我们出去散了步。正：The weather being fine, we went out for a walk. 正：The weather was fine, and we went out for a walk. 教室里包括老师有五个人。正：In the classroom there are five people, the teacher included. 正：In the classroom there are five people, and the teacher was included. 他有两个小孩，都很顽皮(from )。正：He has two children, both of whom are naughty. 正：He has two children, and both of them are naughty. 2. bothand的用法其意为“和都”、“不但而且”、“既又”：She both speaks and writes Japanese. 她不仅会说日语，而且还会写。He spoke with both kindness and understanding. 他说话既亲切又明事理。【注】作为关联并列连词，它通常应连接两个相同性质的句子成分，但有时后一成分可能省略与前一成分相同的词。另外，若连接两个成分作主语时，谓语要用复数：Both she and Sophia were pleased with the girl. 她和索菲娅都喜欢这姑娘。3. neithernor的用法其意为“既不也不”、“和都不”：I have neither time nor money. 我既无时间又无钱。I neither smoke nor drink. 我既不抽烟也不喝酒。He neither knows nor cares what happened. 他对所发生的事不闻不问。This is neither my fault nor yours. 这既不怪我，也不怪你。【注】通常应连接两个相同性质的句子成分，但有时后一成分可能省略与前一成分相同的词。若连接两个成分作主语，其谓语通常与靠近的主语保持一致：Mary neither likes maths nor (likes) history. 玛丽既不喜欢数学也不喜欢历史。Neither Jim and Jack was at home. 吉姆和杰克都不在家。4. not onlybut also的用法其意为“不但而且”：Not only A but also B=B as well as A,但是前者的强调重点在B,后者的强调重点也在B.The child is not only healthy but also lively.=the child is lively as well as healthy.这孩子既健康又活泼。Not only men but also women were chosen. 选中的不仅有男的也有女的。He not only read the book, but also remembered what he read. 他不仅读过这本书，而且还记得书中的内容。【注】该结构中的also有时可省略，或与but分开用，或用too, as well代之(位于句末)：Not only is he funny, but he is witty too as well. 他不但风趣，而且也很机智。若连接两个成分作主语，其谓语通常与靠近的主语保持一致：Not only you but also he has to leave. 不只是你，他也得离开5As well as的用法1. as well as 可连接并列的单词或短语。例如： It is unpleasant in summer as well as in winter. 夏天不好过，冬天也不好过。 The child is lively as well as healthy. 这孩子既健康又活泼。 2. as well as 连接两个谓语动词时，它们的时态应保持一致。例如： He publishes as well as prints his own books. 他的书是他自己印刷出版的。 We are repairing the roof as well as painting the walls. 我们在粉刷墙壁同时也在修理屋顶。 as well as 与动词连用时，其后可用V-ing形式，尤其as well as 位于句首时，此时相当于in addition to。例如： As well as breaking his leg, he hurt his arm. 他不但摔断了腿，而且还伤了胳膊。 She sings as well as playing the piano. 她不但会弹钢琴，而且会唱歌。 3. 如果as well as 前面是动词不定式，那么其后的动词也是不定式，但to要省略。例如： You cannot expect her to do the housework as well as look after the children. 你不可能叫她既照顾孩子又做家务。 4. 由as well as 连接的复合主语并不影响谓语动词的数。例如： Helen as well as I is eager to see the performance. 海伦和我一样急于要看演出。 I as well as they am ready to help you. 不仅他们愿意帮助你，我也愿意帮助你。 5. as well as 连接的人称代词既可以是主格也可以是宾格，但句意不同。例如： They have invited you as well as me. 他们邀请了我，也邀请了你。（you和me都作invited的宾语） They have invited you as well as I. 他们和我一样都邀请了你。（they和I都作invited的主语） 6. as well as 用于肯定结构和否定结构中，其意义不同。as well as 和not搭配使用，as well as 位于not前时，两者均否定；位于not后时，否定前者，肯定后者。例如： George, as well as his brother, has gone abroad. 乔治和他兄弟一样都出国了。 George, as well as his brother, hasnt gone abroad. 乔治和他兄弟都没有出国。 George hasnt gone abroad as well as his brother. 乔治并没有和他兄弟一样出国去。（他兄弟一人出国） 7. as well as 在意义上通常强调前者，而not only but also在意义上则强调后者。例如： Hes got a car as well as a motorbike. 他不但有一辆摩托车，而且有一辆小汽车。 （= He”s got not only a motorbike but also a car. ） 6 then的用法1）表示“然后”、“接着”，通常与连词 and 连用。如：Lets go for a drink and then go home. 我们先去喝一杯，然后再回家。He went to Paris, and then to London. 他到了巴黎，后又到了伦敦。注：在口语中有时可不用连词 and 而只用 then。另外，有时位于句首，其后用倒装句。如：Then came the day of his exam. 接着他考试的那一天到了。2）表示“那么”、“既然是那样”、“这么说来”，通常用于句首或句末。如：You say you dont want to be a teacher. Then what do you want to be? 你说你不想当老师，那么你想干什么呢? Then you mean to say I am a cheat. 那么你的意思是说我是个骗子。注：有时与条件或时间状语从句搭配使用。If its not on the table, then it will be in the drawer. 要是不在桌上，那就是抽屉里。When I know what really happened, then I shall be able to decide. 当我知道事实真相后，我就可以作决定了。2）表示选择的并列连词1.or的用法（1）.表示选择，意为“或”“还是”：Is the radio off or on? 无线电关上了还是开着的?Would you prefer tea or coffee? 你喜欢茶还是咖啡？Is he asleep or awake? 他睡着了还是醒着?Are you going to America by boat or by air? 你到美国是坐船还是坐飞机？（2）.表示一种否定的条件，意为“否则”：Come on, or well be late. 快点，否则我们要迟到了。Dress warmly, or else youll catch cold. 穿暖和点，否则你会感冒的。Be careful, or youll break that vase! 小心，否则你会把那花瓶打碎!Cross the road very carefully. Look both ways, or you might be knocked down. 过马路要非常小心，要看两边，不然会被车撞倒。（3）.可表示“要不就是”：He must be joking, or else hes mad. 他一定在说笑话，要不就是疯了。The book must be here, or else youve lost it. 这书一定在这儿，要不就是你丢失了。（4）.用于否定句中代替and。He was not clever or good-looking. 他不聪明，也长得不好看。比较：They sang and danced. 他们既唱歌又跳舞。They didnt sing or dance. 他们既没有唱歌也没有跳舞。（5）.用于习语(from )The work is more or less finished. 工作大体上完成了。Theres just one or two details I want to make sure about. 还有一两个细节我想弄清楚。Either your mother or your father may come with you. 你母亲或是你父亲会陪你去。2. eitheror的用法其意为“要么要么”、“不是就是”：Either come in or go out. 要么进来，要么出去。I want to visit either Paris or London. 我想去巴黎或伦敦游览一下。Either he did not speak distinctly or I did not hear well. 不是他没讲清楚，就是我没听明白。【注】通常应连接两个相同性质的句子成分，但有时后一成分可能省略与前一成分相同的词。若连接两个成分作主语，其谓语通常与靠近的主语保持一致：You can either have tea or coffee. 你喝茶也行，喝咖啡也行。Either you or I am wrong. 不是你错，就是我错。3）表示意义转折或对比的并列连词1.but 与 however的用法区别两者均可表示转折或对比，意为“但是”、“可是”、“然而”等，但有区别：（1）. 表示转折时，but 是连词。如：He is young but very experienced. 他虽年轻，但经验很丰富。He has three daughters but no sons. 他有3 个女儿，但没有儿子。He likes sports, but his wife likes music. 他喜欢运动，而他妻子则喜欢音乐。（2）. however 表示“然而”、“可是”时，有的词书认为它是连词，有的词书认为它是副词。之所以将其视为副词，也许是因为像许多副词一样不仅能位于句首，而且能位于句中(注意前后使用逗号)，甚至句末 (注意其前也用逗号)。如：Later, however, he changed his mind. 可是他后来改变了主意。He hasnt arrived. He may, however, come later. 他还没有到，不过他等会儿可能会来。He said that it was so; he was mistaken, however. 他说情况如此，可是他错了。注：以上各例中的 however 不能换成 but，但可用 but 来改写。如：He said that it was so, but he was mistaken. 他说情况如此，可他错了。（3）. 当连接两个句子时，其前通常应用分号，或另起新句。如：Its raining hard. However, I think we should go out. 雨下得很大，但我想我们还得出去。注：上例中的 however 不能换成 but，但可用 but 来改写 (注意所用标点的变化)。如：Its raining hard but I think we should go out2.yet的用法yet用作并列连词，主要表示转折，意为“然而”“但是”。如：He worked hard, yet he failed. 他工作努力，可是他失败了。He said he would be late, yet he arrived on time. 他说他会迟到，但他却准时到了。在使用时还要注意以下几点：（1）. 用于习语and yet或but yet，意为“虽然如此”“可是”“然而”，与单独使用的yet意思相同。如：Hes not really nice-looking, and yet he has enormous charm. 他并不十分好看，可是他很有魅力。Shes a funny girl, but yet you cant help liking her. 她是一个奇怪的姑娘，但你禁不住会喜欢她。（2）. 根据英语习惯，although不能与连词but搭配使用，但是有时although可以与yet搭配连用（此时的yet可视为副词）。如：Although we are poor, yet we are happy. 尽管我们穷，但我们很快活。3. while的用法while用作连词时，有以下几种含义：（1）、意为“当时候，和同时”，引导时间状语从句。例如：While I was watching TV，the bell rang.我看电视时，铃响了。）Tom watched TV while she ate her supper.（汤姆边吃晚饭边看电视。）（2）、意为“虽然，尽管”，引导让步状语从句。例如：While it was late，he went on working.（虽然很晚了，但他还在继续工作。）While he is in poor health，he works hard.（虽然他身体不好，但他还是努力工作。）（3）、连接两个并列句子，表示“对比”关系。例如：He went out for a walk，while I stayed at home.（他出去散步了，而我却呆在家里。）I like singing while she likes dancing.（我喜欢唱歌，而她喜欢跳舞。）You like sports，while I prefer music.（你喜欢体育，而我更喜欢音乐。）4.whereas的用法whereas只有一种用法，就是用于比较或对比两个事实。如：American cars are generally too large for Japanese market, whereas Japanese cars are popular in the US.4. not.but句子中，but是连词，构成转折，表示对比，译为“不是而是”，句子前后具有否定，肯定的对等意义。She is not a student, but a worker.她不是学生，而是工人。notbut的这种用法和not thatbut (that) 的用法一样。Not that I dislike the task, but that I am unequal to it.不是我不喜欢这个工作，而是我不干了。5.only的用法用作并列连词时，意为“但是、可是、可惜、不过”。如： This dictionary is just what I want, only it costs too much. 这本词典正是我想要的，但是太贵了。 He is always ready to promise help, only he never keeps his promise. 他总是轻易许诺提供帮助，但是他从不遵守诺言。 The flowers are lovely, only they have no scent. 这些花朵很好看，可异没有香气。 I would do it with pleasure, only I am too busy. 我倒是很高兴去做，可是我太忙了。 You may come at any time, only you had better let me know beforehand. 你什么时候来都行，不过最好先告诉我一声。 4）表缘由的并列连词for用作连词，主要表示理由，用于引起的分句对前面的话进行解释，常用逗号把它和前面的分句分开。如：She was angry, for she didnt know French. 她生气了，因为她不懂法语。He must be out, for there is no light in the room. 他准是出去了，因为屋里没有灯。He shook his head, for he thought differently. 他摇了摇头，因为他有不同想法。The days were short, for it was now December. 白天很短，因为这时已经是十二月。She does not go out in the winter, for she feels the cold a great deal. 她冬天不出门，因为他特别怕冷。for表示结果通常不能放句首，也不能单独使用。Because since as for的用法区分：四者均可用来表示原因，区别如下：(1) 关于 because：语气最强，表示直接原因，可用于回答 why 提出的问题、引导表语从句、用于强调句等，而其余三者均不行：“Why didnt he come?” “Because he was ill.” “他为什么没来?”“因为他病了。”My stomach hurts because I have eaten too many apples. 我肚子痛，因为苹果吃得太多。Thats because you cant appreciate music. 这是因为你不能欣赏音乐。 (2) 关于 since 与 as：a. 两者所表示的原因都是人们已知的，即对已知事实提供理由，而不是表示直接原因。since 比 as 语气稍强，且比 as 略为正式，它们引导的从句通常放在主句之前，有时也放在主句之后：As you werent there, I left a message. 由于你不在那儿，我留了个口信。Since you are wrong, you should apologize. 你既然错了，就应该道歉。b. since 可用于省略句，而其他三者不行：Since so, I have nothing to say. 既然如此，我无话可说。(3) 关于 for：是并列连词(其余三者为从属连词)，它有时可表示因果关系(通常要放在主句之后，且可与 because 换用)；有时不表示因果关系，而是对前面分句内容的解释或推断(也要放在主句之后，但不能与because 换用)。比较：The ground is wet, for (=because) it rained last night. 地面是湿的，因为昨晚下过雨。It must have rained last night, for the ground is wet this morning. 昨晚一定下过雨，你看今天早上地面是湿的。 (此句不能用 because 代 for)2. 从属连词及其用法1）简单从属连词从属连词是指在复合句中引导从句的连结词。常见的从属连词有：引导时间状语从句的：after, before, when, as, while, since, until, till, as soon as 引导原因状语从句的：because, since, as引导让步状语从句的：although, though, no matter（无论）, even if (though)引导条件状语从句的：if, unless, once, so (as) long as 引导结果状语从句的：so that , such that 引导目的状语从句的：so that , in order that 引导比较状语从句的：as as , not so (as) as , than 引导方式状语从句的：as if 引导主语，宾语或表语从句的连词主要有：that, whether, if三个。其中that 和whether间或还可以引起同位从句和状语从句。（1）although与 though的同与异1. 用作连词，表示“虽然”，两者大致同义，可换用，只是 although 比 though 更为正式。如：Though Although theyre expensive, people buy them. 虽然它们很昂贵，人们还是买。2. though 可用作副词，表示“可是”“不过”，常用逗号与句子分开。although则不能这样使用，它只作连词。例如：It was a quiet party, I had a good time, though.I expect youre rightIll ask him, though. 我认为你说得对我去问问他也好。She promised to phone. I heard nothing, though. 她答应要打电话来. 可我没听到回信儿。这样用的though通常位于句末，但有时位于句首的though也有这样的意思。如：他说他要付钱，然而我认为他不会付的。正：He says hell pay, though I dont think he will.正：He says hell pay; I dont think he will, though.though常与even连用，even though表示强调，意为“即使”，但不能说even although，例如：Even though I didnt understand a word, I dept smiling.3. 在 as though（好像，仿佛），even though（即使，纵然）等固定短语中，不能用 although代替though。如：She treats me as though I were a stranger. 她待我仿佛我是一个陌生人。Hes the best teacher even though he has the least experience. 他尽管经验最少，但教得最好。4. 两者均可用于省略句，通常见于主句与从句主语相同，且从句谓语含有动词be的情形。如：Although Though (it was) built before the war, the engine is still in perfect order. 尽管是战前制造的，这台发动机仍然处于良好状态。Although Though (he is) still young he is going very grey. 尽管他还年轻他的头发却已变得灰白。Although Though (she was) in pain, she bravely blinked back her tears. 她虽然很疼痛，但还是硬把眼泪抑制住了。5. 当though用于倒装形式，它不能换成although，但可换成as。Successful though as he is, he is not proud. 他虽然成功，但不骄傲。Much though as I like you, I couldnt live with you. 我尽管很喜欢你, 却不能和你在一起生活。Try though as I would, I could not make her change her mind. 不管我多努力，也不能让她改变主意。Surrounded though as we were by the enemy, we managed to march forward. 虽然我们被敌人包围着，但我们还是设法前进了。Raining hard though as it is, Im going out for a walk. 虽然正在下着大雨，我还是要出去散步。注意，若倒装后置于句首的是名词时，其前习惯上不用冠词或其他限定词。如：Expert though as he was, he failed. 他虽是专家，但还是失败了。Big puzzle though as it was, it hadnt got the better of Jim. 虽然是个大难题，但仍没有难倒吉姆。6. 不要按汉语“虽然但是”的表达习惯，在 although 后连用 but。如：虽然他只是个业余爱好者，但却是一流的高手。误：Although hes only an amateur, but hes a first-class player.正：Although hes only an amateur, hes a first-class player.但是在强调时，although 可与 yet, still 等副词连用。如：Though he seems happy, yet he is worried. 虽然他看起来很幸福，但他实际上很烦恼。（2）since的用法作为连词，since可引导原因状语从句，表示因为；既然；鉴于：例如：1 He didnt come since he was busy.他因为忙，所以没有来。2 Since this method doesnt work, lets try another.既然这种方法不行，我们就试用另一种吧。（3）once的用法once用作连词时，意为“一旦就”，用于连接时间状语从句，相当于as soon as。如： Once you start, you will never give up. 一旦你开始了，你就不要放弃。 注意：once引导的是时间状语从句，从句要用一般现在时代替将来时。（4）until 意为“一直到”，其相应主句的谓语只能是持续性的，而不能是终止性的。它表示的是：主句动作一直持续到从句动作发生时为止。We waited until he came. 与 until 从句连用的主句谓语不能是终止性动词，但是若这个谓语是否定的，则可以是终止性动词，因为终止性动词一旦被否定，即成为状态，而状态都是可以持续的(注：not.until.意为：直到才)：误：We stopped until he came. 正：We didnt stop until he came. 直到他来我们才 停止。误：We started until the rain stopped. 正：We didnt start until the rain stopped. 直到 雨停我们才开始。误：He finished it until it was dark. 正：He didnt finish it until it was dark. 直到 天黑他才完成。(5) while的意思是“在同时（at the same time that )”“在期间(for as long as, during the time that）”。从while的本身词义来看，它只能表示一段时间，不能表示具体的时间点。在时间上可以是“线线重合”或“点线重合”，但不能表示“点点重合”。例如： 1、He was watching TV while she was cooking. 她做饭时，他在看电视。（线线重合） 2、 He was waiting for me while I was working. 我工作的时候，他正等着我。（线线重合） 3、 He asked me a question while I was speaking. 我在讲话时，他问了我一个问题。（点线重合） 表示让步，意为“尽管”“虽然”。如：While the work was difficult, it was interesting. 虽然工作有难度，但很有趣。While we dont agree we continue to be friends. 尽管我们意见不同，我们还是朋友。While he admitted that he had received the stolen jewellery, he denied having taken part in the robbery. 尽管他承认他收受了盗窃的珠宝，但他否认参与了抢劫案。While I did well in class, I was a poor performer at games. 虽说我学习不错，我运动却不行。While a few became richer, many did not. 虽然一些人变得更富有了，但多数人并非如此。表示对比或转折，意为“而”“但是”。如：I went swimming while the others played tennis. 我去游泳，而其余的人则去打网球了。Air is a fluid but not a liquid, while water is both a fluid and a liquid. 空气是流体不是液体，水是流体也是液体。Some people waste food while others havent enough. 一些人糟踏食物而另一些人却食不果腹。注：这样用时，while引出的句子通常位于末，但有时也可位于句首。如：While most children learn to read easily, some need extra help. 大多数儿童学会阅读很容易，有一些儿童却需要特别帮助。 (6) when的意思是“当时候（at the time that）”“无论什么时候（whenever）” “一就（as soon as ）” “在以后（after）”。它表示的时间概念比较广泛，上述例句中的as或while均可用when代替，因为when不但可以表示具体的时间点，而且也可以表示一段时间。在时间上它既能表示“点点重合”“线线重合”，又能表示“点线重合”。例如： 1、When he came in，she went out. 他进来，她出去。（点点重合） 此句中when从句的动作表示的是一个时间点，when可以用as代替，但不能用while代替。 2、When he came back，I was doing some washing. 他回来时，我在洗衣服。（点线重合） 此句中when从句的动作表示的是一个时间点，所以只能用as代替，不能用while代替。 3. When Mary was writing a letter, the children were playing outside. 玛丽写信时，孩子们都在外面玩。（线线重合） 此句中的when从句的动作表示的是一段时间，故可用as 或 while代替。当while, when, as引导时间状语从句时的区别：while引导的状语从句中动词必须是持续性。谓语动词多为进行时，或状态动词的一般时。while 的这些用法可用when代替，等于 “at the time that”, “during the time that”。例如：Please keep quiet while (when) others are studying； when除可指一段时间外，还可用来指一点时间，等于 “at the time”，也就是说when引出的时间状语从句中的谓语动词可以是终止性的，也可以延续性的。因此主句和从句的谓语可以是一般时，进行时，或完成时。例如：When I went into the lab, the teacher was doing an experiment.（when不能换成while）He often makes mistakes when he is speaking English.（when可换成while）as常可与when，while通用，但强调“一边、一边”。例如：As (when, while) I was walking down the street, I noticed a police car in front of number 37. when引导的状语从句中的主语与主句主语一致，主、谓是“主语+系动词”结构时，这时主语和系动词可以省略。例如：When (he was) young, he worked for a rich man./ Shell be here to give you help when (if it is) necessary. (7) if和whether通用，都表示“是否”的意思。一般来说，后者比较正式，在口语中前者常用来代替后者。但两者有时具有不同的暗示。用whether时，正反两面的选择意义较强，问话人并不在意回答是肯定还是否定；而用if时，则比较强调单方面，即正面，问话人希望得到肯定的回答。另外，还要注意以下几点：一、whether和if都可以与or not连用；但写在一起时，只能用whether，不能用if。如： I dont care whether (或if) it will rain or notI dont care whether or not it will rain. (不用if)二、在引导宾语从句时，应注意：宾语从句为否定形式时，通常用if，而不用whether。I asked Tom if Mary wouldntt come.whether和if均可用来引导主语从句，但if引导的从句不能位于句首。如： Whether they win or lose is all the same to me. 他们是赢是输於我都一样.（此时whether不能换作if ） Its doubtful whether therell be any seats left. 说不上还有没有空座位了. (此句whether能换作if) 2.whether和if均可用来引导宾语从句。如：I dont know whether/if I will be able to come.我不知道我是否能来. She asked me whether/if I was interested in working for her.她问我是否有兴趣为她工作。Well be told tomorrow whether we should take the exam or not.我们明天才知道是不是应该参加考试. I asked him whether he had done all the work himself o