Unit 5 语法专项课件— 现在完成时 课件 2025-2026学年北师大版英语八年级上册

教学课件 北师大英语八年级上册 Unit5语法专项——现在完成时 全解精讲+分层练习 1 学习目标 掌握现在完成时的核心含义、两种主要用法及适用场景 熟记现在完成时的肯定、否定、疑问句式结构,能灵活变换 掌握for、since及ever、never等时间状语的用法,精准匹配语境 牢记动词过去分词的变化规则(规则+不规则),能正确书写 能综合运用现在完成时完成各类题型,提升语境应用能力 现在完成时 核心引入 现在完成时是初中英语核心语法,连接过去与现在,重点突出“关联” 它不单纯描述过去的动作,也不单纯描述现在的状态,而是体现两者联系 例句1:I have read this book.(我读过这本书,强调现在知道书的内容) 例句2:I read this book yesterday.(仅说明昨天读了,无现在关联) 本单元将从含义、结构、时间状语、分词变化四个维度详细讲解 现在完成时 核心含义(一) 含义1:动作从过去开始,持续到现在,重点强调“持续性” 核心标志:常与for(后接时间段)或since(后接时间点/从句)连用 关键提醒:动作是“可延续”的,不能是瞬间完成的动作(如die、buy) 例1:I have loved travelling since I was a child.(从小喜欢,现在仍喜欢) 例2:She has learned English for five years.(学了五年,现在还在学) 现在完成时 核心含义(二) 含义2:过去的动作对现在有影响或留下痕迹,重点强调“结果/经历” 核心标志:常与ever、never、just、already、yet等副词连用 关键提醒:不强调动作发生的具体时间,只关注对现在的影响 例1:These trips have changed my life.(旅行在过去发生,现在生活已改变) 例2:I have just finished my homework.(刚做完,现在可以休息了) 现在完成时 句式结构总览 助动词:have/has(第三人称单数用has,其余人称用have) 动词形式:动词过去分词(V-ed),无人称和数的变化 肯定句:主语 + have/has + 动词过去分词 否定句:主语 + have/has + not + 动词过去分词(缩写为haven’t/hasn’t) 一般疑问句:Have/Has + 主语 + 动词过去分词?(回答用Yes/No) 特殊疑问句:疑问词 + have/has + 主语 + 动词过去分词? 现在完成时 肯定句与否定句详解 肯定句:主语+have/has+V-ed,表“已经做了/持续了某事” 例1:He has lived in Beijing for 3 years.(他在北京住了3年,现在还在) 例2:We have visited that museum twice.(我们去过两次,有这个经历) 否定句:主语+haven’t/hasn’t+V-ed,表“没做过/没持续某事” 例1:I haven’t seen him since last month.(从上个月起就没见过他) 例2:She hasn’t finished her work yet.(她还没完成工作,影响现在安排) 现在完成时 疑问句详解 一般疑问句:Have/Has提前,主语后接V-ed,句末用问号 肯定回答:Yes, 主语 + have/has. 否定回答:No, 主语 + haven’t/hasn’t. 例1:—Have you ever been to Shanghai? —Yes, I have./No, I haven’t. 特殊疑问句:疑问词(what/who/how long等)+ 一般疑问句语序 例1:How long have you studied English?(你学英语多久了?) 例2:What have you done today?(你今天做了什么?) 时间状语详解(一)for + 时间段 核心含义:表示动作或状态持续的“时长”,从过去持续到现在 结构:for + 具体时间段(不能接时间点) 常见搭配:for three weeks(三周)、for a long time(很长时间) 例1:I have stayed here for three weeks.(我在这里待了三周了) 例2:They have worked together for five years.(他们一起工作五年了) 易错点:for后不能接“yesterday、2020年”等时间点,只能接时长 时间状语详解(二)since + 时间点/从句 核心含义:表示动作的“起点”,从过去某一时间开始,持续到现在 两种结构:1. since + 过去时间点(如since 2010、since last week) 2. since + 一般过去时从句(如since I was 8、since we met) 例1:He has lived here since 2010.(从2010年起就住在这里) 例2:We have been friends since we met at school.(从上学见面就是朋友) 技巧:since后接的动作是“过去的瞬间”,主句动作是“持续的” 时间状语详解(三)常见副词用法表 句式类型 副词 位置 含义 例句 肯定句 already 句中(have/has后)/句末 已经 We have already finished our work. 肯定句 just 句中(have/has后) 刚刚 He has just arrived. 否定句 never 句中(have/has后) 从未 I have never been to Paris. 否定句/疑问句 yet 句末 还,仍 They haven’t left yet. 疑问句 ever 句中(have/has后) 曾经 Have you ever tried this food? 时间状语 易错点提醒 1. already,yet的区别:already用于肯定句,yet用于否定句/疑问句(句末) 错误:I have yet finished my homework. 正确:I have already finished it. 2. since和for不可混用,since接起点,for接时长,可互相转换 例:He has lived here since 2020. = He has lived here for 4 years. 3. 现在完成时不与yesterday、last year等“过去具体时间”连用 错误:I have visited him yesterday. 正确:I visited him yesterday. 动词过去分词 规则变化(一) 过去分词是现在完成时的核心,分为规则变化和不规则变化 1. 一般情况:直接在动词原形后加-ed,发音多为/d/或/t/ 例:work worked 、visit visited 、play played 2. 以-e结尾的动词:直接加-d,无需重复加-e 例:love loved、change changed、like liked 技巧:以-e结尾的动词,变化最简单,直接加-d即可,不易出错 动词过去分词 规则变化(二) 3. 以“辅音字母 + y”结尾的动词:先变y为i,再加-ed 例:study studied 、carry carried(搬运)、try tried(尝试) 注意:若y前是元音字母(a/e/i/o/u),则直接加-ed,无需变y 例:play played、stay stayed(y前是元音a) 4. 重读闭音节动词(辅元辅结构):双写末尾辅音字母,再加-ed 例:stop stopped 、plan planned 、shop shopped 动词过去分词不规则变化(高频) 动词原形 过去分词 中文含义 例句(现在完成时) go gone 去 He has gone to school. see seen 看见 I have seen this movie. be been 是/在 They have been here for an hour. do done 做 She has done her homework. find found 找到 I have found my keys. eat eaten 吃 I have eaten breakfast. take taken 拿/带 She has taken my book. 动词过去分词不规则变化(高频) 动词过去分词 易错点汇总 1. 混淆规则变化:“辅音+y”结尾,忘记变y为i,如study studied(非studyed) 2. 重读闭音节漏双写:stop stopped(非stoped)、plan planned(非planed) 3. 不规则动词记混:如go的过去分词是gone(非went,went是过去式) 4. 误将过去式当过去分词:如see的过去式是saw,过去分词是seen 技巧:每天记忆5个不规则动词,结合例句记忆,避免死记硬背 小练习(一)- 时间状语填空 用for、since、already、yet、just、ever、never填空,注意用法匹配 1. I have lived in this city _ 2018.(从2018年起) 2. She has studied Chinese _ three years.(持续三年) 3. They have _ arrived at the airport.(刚刚到达) 4. Have you _ been to the Great Wall?(曾经去过) 5. We haven’t finished our project _.(还没完成) since for just ever yet 小练习(二)- 动词过去分词填空 写出下列动词的过去分词,巩固变化规则 1. work _ 2. love _ 3. study _ 4. stop _ 5. go _ 6. see _ 7. do _ 8. plan _ 9. carry _ 10. find _ worked loved studied stopped gone seen done planned carried found 小练习(三)- 句式变换 1. I have finished my homework.(改为否定句) 2. She has lived here since 2015.(改为一般疑问句) 3. They have stayed in Beijing for two months.(改为否定句) 4. He has just received a letter.(改为一般疑问句并作肯定回答) I haven’t finished my homework. Has she lived here since 2015? They haven’t stayed in Beijing for two months. Has he just received a letter? Yes, he has. 综合练习(一)- 单项选择 从A、B、C、D四个选项中,选出最佳答案 1. My brother _ English for six years. He speaks it well. A. learn B. learned C. has learned D. will learn 2. —Have you _ visited the Summer Palace? —No, I haven’t. A. ever B. never C. already D. yet 3. She _ her homework yet. She can’t go out to play. A. doesn’t finish B. didn’t finish C. hasn’t finished D. won’t finish C A C 综合练习(二)- 单项选择 4. We _ just _ our plan for the trip. A. have; finish B. have; finished C. has; finished D. did; finish 5. He _ in Shanghai since he was born. A. lives B. lived C. has lived D. will live 6. They have _ done lots of work, so they can rest now. A. already B. yet C. never D. just 7. —How long have you stayed here? —I have stayed here _ a week. A. since B. for C. in D. on B C A B 综合练习(三)- 用所给词适当形式填空 1. I _ (be) to Beijing twice. It’s a beautiful city. 2. She _ (love) reading since she was a little girl. 3. We _ just _ (receive) a gift from our teacher. 4. They _ (not visit) the new museum yet. 5. He _ (stay) in London for three months last year. have been has loved have received haven’t visited stayed 综合练习(四)- 用所给词适当形式填空 6. Have you ever _ (try) this kind of cake? It’s delicious. 7. I’ve never _ (see) such a wonderful show before. 8. She _ (change) a lot since we last met two years ago. 9. We have already _ (pack) our bags for the trip. 10. Has he _ (find) his lost watch yet? tried seen has changed packed found 综合练习(五)- 句型转换 1. He has lived in this village since 2010.(对划线部分提问) 2. I have already read this novel.(改为否定句) 3. They have stayed here for five days.(对划线部分提问) 4. Have you ever been to New York?(作肯定回答) 5. She has finished her housework.(改为一般疑问句) How long has he lived in this village? I haven’t read this novel yet. How long have they stayed here? Yes, I have. Has she finished her housework? 综合练习(六)- 完成句子 1. 我已经学英语八年了。 I _ _ English for eight years. 2. 他从十岁起就喜欢画画。 He _ _ drawing since he was ten years old. 3. 你曾经去过国外吗? Have you _ _ abroad? 4. 他们还没有决定去哪里。 They _ _ where to go yet. have learned has loved ever been haven’t decided 综合练习(七)- 完成句子 5. 我刚刚收到了我朋友的邮件。 I have _ _ an email from my friend. 6. 她从未去过长城。 She has _ _ to the Great Wall. 7. 我们已经完成了我们的任务。 We have _ _ our task. 8. 他在这里待了一个月了。 He has stayed here _ a month. just received never been already finished for 语法拓展 - 现在完成时与一般过去时的区别 两者均涉及过去动作,但侧重点不同,是考试高频易错点 1. 现在完成时:强调过去动作与现在的联系(影响/持续),不接具体过去时间 例:I have eaten breakfast.(吃过了,现在不饿) 2. 一般过去时:仅描述过去发生的动作,与现在无关,接具体过去时间 例:I ate breakfast at 7 o’clock.(仅说明7点吃了,不涉及现在) 技巧:看是否有“现在关联”,有则用现在完成时,无则用一般过去时 语法拓展 - 瞬间动词与延续动词的转换 瞬间动词(如buy、die、start)不能与for/since连用,需转换为延续动词 常见转换:buy have had;borrow have kept;die have been dead 例:错误:I have bought this book for 2 years. 正确:I have had this book for 2 years.(我买这本书两年了) 例:错误:He has died since 2020. 正确:He has been dead since 2020. 核心:延续动词才能表示“持续一段时间”,瞬间动词无法持续 语法知识总结(一)- 核心含义与结构 1. 核心含义:① 过去动作持续到现在(for/since); ② 过去动作对现在有影响(ever/never等) 2. 核心结构:have/has + 动词过去分词(V-ed),人称决定用have还是has 3. 句式变换:否定句加not(缩写haven’t/hasn’t),疑问句提前have/has 4. 关键:不强调动作发生的具体时间,强调与现在的关联 5. 易错点:不与具体过去时间(yesterday等)连用 语法知识总结(二)- 时间状语与分词 1. 时间状语分类:for(时长)、since(起点)、ever/never/just/already/yet(副词) 2. 副词用法:already(肯定句)、yet(否定/疑问)、just(句中)、ever(疑问) 3. 过去分词:规则变化(4类)+ 不规则变化(重点记忆高频词) 4. 延续动词与瞬间动词:瞬间动词需转换才能与for/since连用 5. 与一般过去时的区别:看“现在关联”,无关联用一般过去时 Unit5 现在完成时 整体总结 学习重点:含义(两种)、结构(肯否疑问)、时间状语、分词变化 解题技巧:先判断语境(持续/影响),再选时间状语,最后确定分词形式 易错点:分词变化、时间状语混用、瞬间动词与延续动词转换 学习方法:结合例句记规则,多做练习练应用,区分易混点 教学课件 Unit5语法专项——现在完成时 Thank you for listening! 33 $