Unit 1 Past and present Grammar课件2025-2026学年译林版八年级英语下册

该初中英语课件聚焦现在完成时，系统涵盖定义、基本结构、时间标志词、动词过去分词变化及句式转换等核心知识点。通过例句分析引导学生总结肯定句、否定句和疑问句结构，从基础规则到时间标志词分类再到动词变化规律，搭建层层递进的学习支架。 其亮点在于采用分类表格梳理动词过去分词变化，结合对比练习区分already/yet等标志词，通过家乡变化对话情境强化运用。注重语言能力培养，如句式转换练习提升表达准确性，思维品质方面引导辨析延续性与短暂性动词差异，助力学生系统掌握语法，教师可高效开展分层教学。

译林版八年级英语下册 Unit 1 Past and present Grammar 译林版八年级英语下册 学习目标 1.掌握现在完成时的定义、基本结构及用法 2.熟记现在完成时的高频时间标志词并灵活运用 3.掌握动词过去分词的规则与不规则变化 4.区分延续性/短暂性动词，学会句式转换 5.辨析have been to与have gone to的用法差异 6.能运用现在完成时完成各类基础题型 We form the past participles of irregular verbs differently. Here are some examples on page 13. I have finished my homework ____. Have you finished your homework ____? A. yet, yet B. yet, already C. already, yet D. already, already Practice：单项选择: 现在完成时常和 already、ever、just、never、recently、yet 等副词以及 since、for 引导的时间状语连用。 e.g. He has not returned the book to me yet. 他还没有把那本书还给我。 He has never visited the Great Wall. 他从没去过长城。 Suzhou classical gardens have been famous for a long time. 苏州园林已闻名许久。 注意：already 常用于肯定句，意为“已经”，而 yet 常用于否定句和疑问句，意为“还”。 He has just gone home. She has already had a holiday this year. It has broken! I have seen my new English teacher. They have bought a new car. You have finished the exercise. We have seen this film before. Read the sentences below and try to summarise the sentence structure. 肯定句：主语 + have / has + 动词过去分词 (+ 其他). 现在完成时基本结构（肯定句/否定句） 句式 核心结构 经典例句 肯定句 主语+have/has+动词过去分词 I have lived here for 5 years. 否定句 主语+have/has+not+动词过去分词 She hasn't finished her homework. 小贴士：第三人称单数主语用has，其余用have；not可缩写为n't 现在完成时的定义 现在完成时是连接过去和现在的时态 核心：体现过去的动作与现在存在关联 主要表达三种核心含义： 1.持续动作：过去发生，持续到现在仍在进行 2.影响动作：过去发生，对现在造成具体影响/结果 3.经历动作：到目前为止的人生经历或动作累计次数 has changed has turned has improved have moved built haven’t visited There are many changes in Sunshine Town... Have a try She has cleaned the kitchen. (改为否定句) She ________ cleaned the kitchen. 2. They have visited some interesting places in China. (改为一般疑问句) ______ they _______ ____ interesting places in China? 3. They have borrowed ten books from the library. (对划线部分提问) _____ _______ books ______ they _________ from the library? hasn’t Have visited any How many have borrowed I haven’t/have not done my homework yet. You haven’t/have not answered my question. We haven’t/have not worked on a farm. They haven’t/have not seen each other for ages. He hasn’t/has not been home for five years. She hasn’t/has not found a new job. It hasn’t/has not finished yet. 否定句：主语 + have / has + not | haven't / hasn’t + 动词过去分词 (+ 其他). Read the sentences below and try to summarise the sentence structure. 现在完成时基本结构（疑问句） 句式 核心结构 经典例句 一般疑问句 Have/Has+主语+动词过去分词？ Have you been to Beijing? 特殊疑问句 疑问词+Have/Has+主语+动词过去分词？ How long have you studied English? 答语：一般疑问句肯定回答Yes, 主语+have/has；否定回答No, 主语+haven't/hasn't 时间标志词——持续类 判断现在完成时的核心依据，持续类表动作延续至今 1.for + 时间段：表动作持续的时长（for 3 years/for a month） 2.since + 过去时间点/从句：表动作起始点（since 2010/since he came here） 3.so far/up to now/until now：到目前为止（可放句首或句末） 例句：We have learned English since 2019. 1. I have seen my new English teacher. Practice 将下列句子变为否定句。 I have not seen my new English teacher. 2. They have bought a new car. They have not/haven't bought a new car. 3. She has already had a holiday this year. She has not/hasn't had a holiday this year yet. Have I ever done it before? Have you practised the piano recently? Have we done it right? Have they gone home yet? Has he worked here long? Has she already sent the fax? Has it worked properly? Read the sentences below and try to summarise the sentence structure. 一般疑问句： Have / Has + 主语 + 动词过去分词 (+ 其他)? 肯定否定回答： Yes, 主语 + have / has. No, 主语 + haven't / hasn't. has changed has turned has improved have moved built haven’t visited Q: Why should we use the present perfect tense? Look at “Grammar check” on page 157. 时间标志词——影响类 影响类表过去动作对现在产生的结果/影响 1.already：已经，仅用于肯定句，放助动词与过去分词之间 2.just：刚刚，仅用于肯定句，位置同already 3.yet：还（未），仅用于否定句/疑问句，放句末 例句：He has just left. / Have you finished the work yet? Have/Has + subject+ done...? Yes, subject + have/has. No, subject + haven’t/hasn’t. Form the sentence structures Look at “Grammar check” on page 157. Pay attention to the structures of the positive and negative sentences in the present perfect tense. ❀since + a specific time 过去的时间点 e.g.He has lived here since 2000. + a sentence in the simple past tense 从句(一般过去时) e.g. He has lived here since he came to Beijing. ❀ for + a period of time 一段时间 e.g. He has lived here for 5 years. Time adverbials ❀ over / in the (past / last) years “在(过去的)这几年间” e.g. Great changes __________ (take) place over / in the past ten years. have taken e.g. We ____________ (learn) many English songs so far. have learned ❀ so far, up to now, until / till now “到目前为止” Talk with your partner about the changes in your hometown, using the present perfect tense A: Hi! Long time no see.I heard you went back to your hometown in Guizhou last month. How was the visit? B: Oh, it's amazing! So many changes have taken place since I left our town five years ago. The old dirt roads have turned into wide streets, and there are even new bus stations. Have you ever seen a village with its own library?Ours has one now-we never had that before! Pay attention to the structures of the yes-no questions in the present perfect tense and their answers. ❀ already “己经” 用于肯定句 句中(助后实前)/句末 e.g. I’ve already had breakfast. = I’ve had breakfast already. “还(没)”用于否定句 句末 “己经” 用于疑问句 句末 I haven’t had breakfast yet. Have you had breakfast yet? ❀ yet 当在肯定陈述句中含有already时，在转换成否定句或疑问句时，要把句中的already 去掉，在句末加上yet. I _______already ________(collect) some stamps. have collected 否：I ________ __________ any stamps______. haven’t collected yet 疑：________ you __________ any stamps______? Have collected yet Time adverbials Talk with your partner about the changes in your hometown, using the present perfect tense A: Wow, that's great. My hometown in Sichuan has changed a lot too. We used to live in small wooden houses, but most families have moved into new buildings. B: Really? My grandma says the government has built a new bridge through the mountain. It used to take two hours to go to the town centre, but now it only takes 20 minutes. Many young people have come back to start businesses-like my cousin, who has opened an online fruit shop. Pay attention to the time adverbials of the present perfect tense. ❀ already “己经” 用于肯定句 句中(助后实前)/句末 e.g. I’ve already had breakfast. = I’ve had breakfast already. “还(没)”用于否定句 句末 “己经” 用于疑问句 句末 I haven’t had breakfast yet. Have you had breakfast yet? ❀ yet ❀ ever “曾经” 用于肯定句/一般疑问句 句中 ❀ never “从未” 用于否定句 句中 e.g. Have you ever eaten Beijing Duck? e.g. He has never read the story. —Have you ______seen the movie? —Yes, I have. never B. ever C. just D. yet Time adverbials 1. I can’t find my key. I’m afraid I ________ it. 2. I won’t go to the cinema with my friends tomorrow. I ____________ the film many times. 3. Can I borrow your dictionary? Sorry, I ____________ it to Sandy. 4. Let’s go home now. The rain ___________. 5. The bus _________. You’d better wait for another 10 minutes. have lost have watched have lent has stopped has left Homework 1. Remember the grammar rules by heart. 2. Remember the Past participle of irregular verbs 3. Finish the exercise. Thank you $