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怎样运用be动词,助动词,情态动词

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怎样运用be动词,助动词,情态动词
速求
e vi 现在时 I am, you are, he is, we are, you are, they are (缩略式 I'm, you're, he's, we're, you're, they're), (否定缩略式 I'm not, isn't, aren't), 过去时 I was, you were, he was, we were, you were, they were (过去时否定缩略式 wasn't, weren't), 过去分词 been, 现在分词 being “Be”除了原形的“be”之外,还有另外七种形式:am, is, are, been, being, was, were. 在句子中,“be”可以是主动词或助动词
1)协助主要动词构成谓语动词词组的词叫助动词.被协助的动词称作主要动词构成时态,语态. 助动词是语法功能词,自身没有词义,不可单独使用,它没有对应的汉译,例如: He doesn't like English. 他不喜欢英语. (doesn't是助动词,无词义;like是主要动词,有词义) 2) 助动词协助主要动词完成以下功用,可以用来: a. 表示时态,例如: He is singing. 他在唱歌. He has got married. 他已结婚. b. 表示语态,例如: He was sent to England. 他被派往英国. c. 构成疑问句,例如: Do you like college life? 你喜欢大学生活吗? Did you study English before you came here? 你来这儿之前学过英语吗? d. 与否定副词not合用,构成否定句,例如: I don't like him. 我不喜欢他. e. 加强语气,例如: Do come to the party tomorrow evening. 明天晚上一定来参加晚会. He did know that. 他的确知道那件事. 3) 最常用的助动词有:be, have, do, shall, will, should, would
首先它是动词,而且不同于行为动词,行为动词表示的是可以通过行为来表达的动作(如写,读,跑),而情态动词只是表达的一种想法(如能,也许,敢). 用法是:情态动词+行为动词原形 例句:I can read this sentence in English. 我能用英语读这句话. 情态动词是一种本身有一定的词义,表示说话人的情绪,态度或语气的动词,但不能单独作谓语, 只能和其他动词原形构成谓语. We can be there on time tomorrow.我们明天能按时去那儿. May I have your name? 我能知道你的名字吗? Shall we begin now?我们现在就开始吗? You must obey the school rules.你必须遵守校规. 情态动词数量不多,但用途广泛,主要有下列: can (could), may (might), must, need, ought to, dare (dared), shall (should), will (would),have (to) ,had better. 情态动词还有一个很重要的用法,即情态动词表推测—— 情态动词表推测的用法小结 (一)情态动词表推测的三种句式 1.在肯定句中一般用must (一定),may(可能),might / could(也许,或许). (1)He must/may/might know the answer to this question? 他一定/可能/也许知道这个问题的答案. (2)It is cold in the room. They must have turned off the heating. 屋里很冷,他们肯定把暖气关了. 2.否定句中用can’t / couldn’t(不可能), may not/might not(可能不). (1)It can’t/couldn’t be the headmaster. He has gone to America. 这不可能是校长,他去美国了. (2)He may not/might not know the scientist. 他也许不认识那位科学家. 3.疑问句中用can/could (能……?). (1)Could he have finished the task? 他可能把任务完成了吗? (2)Can he be at home now? 他现在能在家吗? 注:以上三种句式中情态动词的语气按程度都是依次递减的.Might, could并非may, can的过去式,而表示语气较为委婉或可能性较小. (二)情态动词表推测的三种时态 1.对将来情况的推测,用“情态动词 + 动词原形”. (1)She must / may / might / could arrive before 5. 5:00前她一定/可能/也许到. (2)She must/may/might/could walk miles and miles among the hills without meeting anyone. 她一定/可能/也许会在山里一连走好几英里而遇不到一个人. 2.对现在或一般情况的推测,用“情态动词 + be”,“情态动词 +be doing”或“情态动词 + 动词原形”. (1)He must / may / might / could be listening to the radio now. 他一定/可能/也许正在听收音机. (2)He can’t ( couldn’t ) / may ( might ) not be at home at this time. 这个时候他不可能/可能不在家. (3)Mr. Bush is on time for everything .How can ( could ) he be late for the opening ceremony ? 布什先生一向准时,这次开幕式他怎么可能迟到呢? 3.对过去情况的推测,用“情态动词 + have +过去分词”. (1)It must / may / might / could have rained last night .The ground is wet. 地湿了,昨晚肯定/可能/也许下雨了. (2)The door was locked. He can ( could ) not / may ( might ) not have been at home . 门锁着,他不可能/可能不在家. (3)Can / Could he have gotten the book? 难道他找到书了吗? 注:情态动词 should /ought to表推测时,意为“想必会,理应……”但与“have +过去分词”连用时,则又可构成虚拟语气意为“本应该做某事却没做”.例如: (4)It’s seven o’clock. Jack should/ought to be here at any moment. 现在七点钟了,杰克理应随时到达.(推测) (5)She should / ought to have attended your birthday party, but she had to look after her mother in hospital. (虚拟) 她本该出席你的生日晚会的,可是她得在医院照顾她妈妈. (6)Tom should not /ought not to have told me your secret, but he meant no harm. (虚拟) 汤姆本不该告诉我你的秘密,可是他并无恶意.