八年级英语语法：现在完成时的用法

1、概念引入如何学习时态？对中学生来说，最好还是从各个时态的基本概念、基本形式和基本用法学起。在过了这一阶段之后，再放开步伐，通过大量的听、读和笔头实践，获得感性的知识。现在，我们就从最基本的概念、形式和用法等方面来总结一种新的时态——现在完成时。2、用法讲解一、现在完成时的定义现在完成时表示过去发生或已经完成的某一动作对现在造成的影响或结果。二、现在完成时的构成1. 肯定句现在完成时的肯定句式是“have（has）＋过去分词”。注意：该句式中的have或has是助动词，has用于第三人称单数，其它人称一律用have。2. 否定句：现在完成时的否定句式是“haven’t（hasn’t）＋过去分词”。3. 疑问句：现在完成时的一般疑问句式是把助动词have或has提到主语之前。回答用Yes, …have(has)./ No, …haven’t(hasn’t).三、 动词过去分词规则变化与不规则变化(一) 规则变化变化规则：与动词过去式规则相同。1. 一般直接在词尾加上ed。look — looked2. 以e结尾的动词，直接加d。move — moved3. 以y结尾，y前面是辅音字母的动词，变y 为i，再加ed。carry — carried4. 部分动词需双写尾字母，加ed。stop — stopped(二)不规则变化不规则动词的变化因词而异。但是如果对不规则动词的过去式和过去分词做一分析，就可发现其中的“规则”。同学们在记忆时，可按下面的形式对教材后不规则动词表进行分析、整理。例如：AAB型原形过去式过去分词中文beatbeatbeaten打败ABC 型原形过去式过去分词中文bewas / werebeen是，在…beginbeganbegun开始blowblewblown吹breakbrokebroken破裂、折断AAA型原形过去式过去分词中文costcostcost花费cutcutcut砍、切、割hithithit打、撞ABA型原形过去式过去分词中文becomebecamebecome成为comecamecome来ABB型原形过去式过去分词中文understandunderstoodunderstood理解、明白bringbroughtbrought带来buildbuiltbuilt建造burnburned/burntburned/burnt燃烧四、现在完成时的用法现在完成时表示过去某时发生的行为对主语目前产生的影响。即用过去发生的某个行为来说明现在的某种情况。例如：We are good friends. (现在的情况）我们是好朋友。I knew him in 1997. (过去的动作) 我1997年认识了他。We have known each other since 1997. 我们自从1997年相互认识。（现在完成时把过去的动作和现在联系起来并着眼于现在）(1) 表示动作发生在过去某个不确定的时间，但对现在留下了某种影响和结果。常被just、already、yet 等副词修饰。例如：— Have you had lunch yet? 你（已经）吃午饭了吗？— Yes, I have. I’ve just had it. 是的，吃过了。我刚刚吃过。（现在我不饿了）(2) 表示从过去某一时刻开始一直持续到现在的动作或状态。这个动作可能刚停止，可能仍然在进行。常带有for和since等表示一段时间的状语。例如：He has taught here since 1981. 他自1981年就在这儿教书。（可能还要继续教）I haven’t seen her for four years. 我有四年没见到她了。(3) 表示说话前发生过一次或多次的动作，现在成为一种经验，一般译为汉语“过”，常带有twice, ever, never, three times等时间状语。例如：I have been to Beijing twice.我去过北京两次。五、现在完成时常用的时间状语before, by now (so far), once, twice…, just, recently, yet(否/疑), already(肯), ever, never, all one’s life , in /during the past /last 5 years    例如：We have already finished our homework. 我们已完成作业了。They haven’t finished their homework yet. 他们还没有完成作业。— Have you ever been to the Great Wall? 你曾经去过长城吗？— I have never been to the Great Wall.我从未去过长城。I have seen her before, but I can not remember where.我以前见过她，但记不起在哪里见过。He has been there three times the last few days.近几天他去过那里三次了。六、现在完成时与一般过去时的比较1) 一般过去时表示过去某时发生的动作或单纯叙述过去的事情，强调动作；现在完成时为过去发生的，强调过去的事情对现在的影响，强调的是影响。I saw this film yesterday. 我昨天看了这部电影。（强调看的动作发生过了。）I have seen this film. 我看过这部电影了。（强调对现在的影响，电影的内容已经知道了。）2) 一般过去时常与具体的表示过去的时间状语连用；现在完成时通常与模糊的时间状语连用，或无时间状语。一般过去时的时间状语：yesterday；last week；…ago；in1990；in October；just now …现在完成时的时间状语：already；ever；  for；just；never；since；yet；so far；till/until；up to now；in the past few years；recently…3) 现在完成时可表示持续到现在的动作或状态，动词一般是延续性的，如：live；teach；learn；work；study；know等；一般过去时常用的非持续性动词有come, go, leave, start, die, finish, become等。She joined the League three years ago.她三年前入团了。 (加入的动作不是延续的)She has been in the League for three years (since three years ago).她入团三年了。(在团内的状态，可延续)She has been a League member for three years (since three years ago).她入团三年了。(是团员的状态，可持续)七、非延续性动词和延续性动词的转换现在完成时可以和带有since或for等表示一段时间的状语连用，表示动作或状态从某一时刻开始，一直持续到现在。但是，像come, arrive, buy等终止性动词不能与表示一段时间的状语连用。要用，必须将其改为相应的延续性动词来表述。现归纳总结一下由非延续性动词到延续性动词的转换：arrive → be herebegin(start) → be ondie →be deadcome back → be backleave →be awayfall ill(sick, asleep)→be ill(sick, asleep)get up→be upgo out→be outfinish →be overput on→wear 或be onopen→be openjoin→be in或 be a member of…close→be closedgo to school → be a studentborrow→keepbuy→havecatch(a cold)→ have(a cold)get to know →knowbegin to study→studycome to work→work例如：He has been a soldier for three years. 他参军三年了。His father has been dead for two years. 他父亲去世两年了。The film has been on for ten minutes. 电影已开始十分钟了。We have studied English for three years. 我们（开始）学英语已三年了。八、have/has gone to；have/has been to；have/has been in的区别have/has gone to：已经去了或在途中，还没有返回；have/has been to：曾经去过某地，现在已经回来了，后面可接表示“次数”的状语；have/has been in：表示某人“已在某地停留一段时间，现仍在那里”，其后常带表示一段时间的状语。 例如：— Where is Tom? Tom 在哪儿？— He has gone to the bookshop to buy some books.他去书店买书了。I have been in Beijing for 5 years.我在北京待了5年了。Jack has been to Shanghai twice. Jack去过上海两次了。巩固练习一、单项填空。1. Li Hong has ________ the army for 2 years.A. joinedB. be inC. been inD. joined in2. We have been friends since ______.A. childrenB. five yearsC. five years agoD. five years before3. Mike ___________ the story for a month.A. has boughtB. has hadC. had hadD. has borrowed4. You ______ that question three times.A. already askedB. have already askedC. already have askedD. asked already5. Those foreign friends left Guangzhou __________.A. since last weekB. a week agoC. for a weekD. since a week ago6. I _____ at this school for two years.A. am studyingB. studyC. studiedD. have studied7. They _________ in the city since last summer.A. liveB. didn’t liveC. have livedD. live8. Mrs. Wang has lived in Haikou _____ 1992.A. sinceB. fromC. afterD. in9. Mr. Black _________Chinasince the summer of 1998.A. has been toB. has been inC. has come toD. came to10. His father _______ for years.A. has diedB. has been deadC. died D. dies[真题链接]1. — Beibei, is Mr. Chen in the office?— No. He       for half an hour.A. leftB. has leftC. has been away2. — Is Miss Green in the office?— No, she ____ to the library.A. goesB. had goesC. has goneD. would go3. — A new shop ______ for a week nearby. Let’s have a look there.— Good idea. But it doesn’t ____ on Mondays.A. opened; openedB. has been opened; openC. has opened; openedD. has been open; open二、用 already或 yet填空。1. Have they taken down the old pictures ____? No, not _______.2. Most of us have finished our compositions ________3. He said he hadn’t visited the exhibition ________.三、用 since或 for填空。1. We have learned five lessons ______ the beginning of this term.2. Mrs. Liao has been in hospital ______last week.3.  I have stayed at my aunt’s _____two weeks.四、用have/has been to/in, have gone to及go的各种形式填空。1. — Where is Jack?— He __________ his country.2. John __________Englandsince he came back.3. How long __________ you __________this village?4. The Smiths __________ Beijing for years.5.  — __________you ever __________ America?— Yes, I __________ there many times.6.  I __________this school since three years ago.7.  — When __________ he __________?— He __________ an hour ago.8. — Would you like to __________ the zoo with me?— Yes, but I __________there before.9. — Where __________ you __________ just now?— I __________ the zoo.10. He often__________ swimming.11. __________ you __________ there last year?12. __________ they often __________skating in winter?五、句型转换，每空一词。1. He has already gone home.He _______ _______ home _________. (否定句)________ he ________ home _________? (一般疑问句)2. He has lunch at home.He ________ _________ lunch at home. (否定句)________ he _______ lunch at home? (一般疑问句)3. He has been there twice. (对划线部分提问)________ ______ _______ ________ he been there?4. I have lunch at school.  (对划线部分提问)________ ________ you _________ lunch.5. They have been here since 2000.________ ________ have they been here? (对划线部分提问)6. This factory opened twenty years ago.(改为同义句)This factory________ ________ ________  for twenty years.7. Miss Gao left an hour ago.  (改为同义句)Miss Gao _______ _______ _______ _______ an hour ago.8. Her mother has been a Party member for three years. (改为同义句)Her mother ______ the  Party  three  years _______ .9. The Green Family moved toFrancetwo years ago. (改为同义句)_______ two years ________ the Green family moved toFrance.10. The bus has arrived here. It arrived ten minutes ago. (把两个句子合并成一个句子)_______________________________参考答案一、单项填空。1. C。现在完成时在肯定句中，与since或for引出的时间状语连用的是延续性动词，不能是短暂性动词。在此题中join是短暂性动词，不能与for+时间段连用，须把它改成相应的延续性动词。此题join要改成be in。这两种词的转换是学习现在完成时需要注意的。2. C。现在完成时表示过去已经开始，一直持续到现在的动作或状态。它的时间状语since + 表过去的时间点，for + 时间段连用。3. B。在肯定句中，与since或for引出的时间状语连用的是延续性动词，不能是短暂性动词，在此题中buy是短暂性动词，不能与for + 时间段连用，须把它改成相应的延续性动词。此题 buy 要改成 has had。4. B。现在完成时表示过去发生或已经完成的动作或存在的状态对现在造成的影响或结果；already 应放在have后面。5. B。该题考查一般过去时。6. D。现在完成时表示过去已经开始，一直持续到现在的动作或状态。与for + 时间段连用。7. C。since是现在完成时的标志词。8. A。本句为完成时态，此处应该选择since； “since + 表过去的时间点”是完成时态的标志性时间状语。9. B。与since或for引出的时间状语连用的是延续性动词，不能是短暂性动词，come是短暂性动词因此选B。10. B。现在完成时与since或for引出的时间状语连用的是延续性动词，不能是短暂性动词，die是短暂性动词,因此要用be dead来代替。[真题链接]1. C。句意：—贝贝，陈先生在办公室吗？—没有，他出去一个小时了。因为题中说道“他出去一个小时了”，所以到应该用延续性动词，故选C。2. C。句意：—格林老师在办公室吗？—不在，她去图书馆了。本题考查动词的时态。由语境可知她去图书馆了，现在还没回来，故选C项。3. D。本题意为：—这附近有一家新开了一周的店，我们去看一下吧。—好主意，但是周一不开门。本题第一空应该用延续性动词，第二空在助动词后面，应该用动词原形。故选D。二、用 already或 yet填空。1. yet; yet   2. already  3. yet三、用 since或 for填空。1. since  2. since  3. for四、用have/has been to/in, have gone to及go的各种形式填空。1. has gone to  2. has been in  3. have; been in  4. have been in   5. Have; been to; have been6. have been in  7. did; go; went  8. go; have been   9. did; go; went to   10. goes11. Did; go   12. Do; go五、句型转换，每空一词。1. hasn’t gone; yet; Has; gone; yet2. doesn’t have; Does; have3. How many times has4. Where do; have5. How long6. has been open7. has been away since8. joined; ago9. It’s; since10. The bus has been here for ten minutes.