Unit 8 Making a Difference Section A 4a-4d课件-2025-2026学年人教版八年级英语下册

该初中英语课件聚焦现在完成时，核心涵盖for/since用法、延续性与非延续性动词转换及与一般过去时的区别。课堂导入通过对话问题引导学生观察for/since差异，结合时间点/时间段分类表格搭建学习支架，帮助梳理语法脉络。 其亮点在于以任务驱动和语境化教学提升语言能力与思维品质，如通过填空、句子判断、语篇填空等练习，结合错误例句对比（如“加入社团”的延续性转换）引导学生分析语法规则。总结环节的动词转换表和小组访谈活动，助力学生掌握学习策略，既让学生在语境中准确运用语法，也为教师提供系统教学资源，提高教学效率。

Unit 8　 Making a Difference Section A Grammar Focus Learning objectives 1.能够梳理和归纳包含for和since的现在完成时的功能和意义，并在语境中准确理解和使用； 2.能够了解现在完成时与持续性时间状语连用的典型动词的特点（延续性动词）； 3.能够在较复杂的语境中理解一般过去时和现在完成时的表意区别，并在语境中合理运用。 Read the sentences. How are for and since used differently? Have you been to our animal shelter before? No, I haven’t. But one of my friends has volunteered here for a long time. Has she ever done volunteer work? Yes, she has. She has been a volunteer at a nursing home since last August. How long have you been a volunteer? I have been a volunteer here for a few months. How long has he worked as a volunteer at the museum? He has volunteered here since his summer holidays started. Engagement since后面接时间点或者一般过去时的句子，强调动作或状态的开始时间。 for后面接时间段，强调动作或状态的持续时间。 -- How long have you been a middle school student? since I was 12. since 2024. -- I have been a middle school student since two years ago. for 2 years. 2024 2 years 2026 Engagement 现在完成时(用法II): 表示过去发生的动作一直延续到现在，而且可能持续到将来。 1:30 three years two months 2025 June 15 one week 时间点 时间点 时间段 时间点 时间段 时间段 时间点指的是具体的时间，比如1点、4月7日、2026年12月； 时间段指的是一段时间内，比如说三点到四点，中间这一个小时就是一段时间。 如何区分时间段和时间点呢？ Exploration 、 1. Mr. Brown has had his TV ________ two years. 2. I’ve learned French _______ last year. 3. Tom has worked in the factory _______ he left school ten years ago. 4. My friends haven’t visited me _______ we finished primary school. 5. She has kept the book Journey to the West _______ one week. 6. Tom has worn glasses _________ two years ago. for since for since since since 用since或for填空。 Practice 1 Complete the sentences with the correct forms of the verbs in brackets and for or since. 4b 1. This college student enjoys volunteering for the army. She __________ (teach) English to the soldiers _____ three years. 2. I __________(be) a member of the Red Cross for six years. I have made a lot of friends _______ I joined the organization. 3. Mr. Wu has taught in a primary school as a volunteer _____ two years now. ______ he started working there, he __________(help) many students. 4. The organization ___________(train) over 6,000 volunteers ________ it began to offer classes three years ago. has taught for have been since for Since has helped has trained since Tips: 先确定主句和从句，再确定since和for,最后确定时态 。 ...的一员 小学 begin to do 开始做某事 Practice 2 军队 大学 一般过去时 vs 现在完成时 核心区别 一、核心定义 1. 一般过去时 (did)只描述过去某个已结束、有明确时间点的动作，和现在完全断开，动作不影响当下。 2. 现在完成时 (have/has done)动作从过去开始，关联现在，无明确过去时间，强调两种结果：①持续到现在 ②对现在造成影响。 二、关键区分点（做题技巧） 1. 时间标志词： 一般过去时，只搭配过去具体时间：yesterday, last year, just now, in 2020, three days ago, then 现在完成时，不能搭配过去具体时间，常见标志词：since + 过去时间，for + 时间段，already, yet, ever, never, so far, recently，同时结合语境 2.注意 ❌ 现在完成时：绝对不能加yesterday、last week这类过去时点 错误：I have volunteered last year. 正确：I volunteered last year. / I have volunteered since last year. Explanation Complete the passage with the correct forms of the verbs in brackets. 4c I love being a volunteer! I ____________(work) with a sports organization for almost three years now. Since I started, I ____________ (help) out at over ten different sports events. I ____________(make) many new friends and I _______ even ______ (meet) many famous athletes. For example, I ______(meet) two national football players from Argentina last month. They were at a stadium for a charity match. The stadium _______(be) so big that they _______ (get) lost. I gave them directions and they ________(smile) and__________(thank) me warmly.I am proud to be a volunteer. have worked have helped have made have met met was got smiled thanked 一般过去时和现在完成时混合训练 Practice 3  延续性动词表示能持续一段时间的动作或表示 状态的词，如work，stay，live，learn等。  非延续性动词表示短暂的动作，从开始到结束， 几乎同时或在极短的时间里就完成，如come，go， leave，start，begin，become，receive，die等。 延续性与非延续性动词 He has joined the music club for two years. He has been a member of the music club for two years. （ ） （ ） 第一课时 1a-2d 他加入音乐社团两年了。 I have bought this watch for two years. I have had this watch for two years. （ ） （ ） 第一课时 1a-2d 这块手表我买了两年了。 判断句子是否正确 Practice 4 、 判断句子是否正确 1 It hasn't died for a year. 2 It hasn't died since it became terribly ill. 在现在完成时否定句中，非延续性动词的否定形式一般认定为延续性，如 haven’t died 没死= have lived一直活着 , haven't left 没离开= have stayed 一直在 haven’t lost 没有丢失= have had/kept一直拥有；持有， 因而可与表示一段时间的状语连用 Practice 4 非延续性动词 对应的延续性表达 例句 begin/start have/has been on The film has been on for 20 minutes. finish/stop have/has been over The parade has been over for 2 hours. come/go/arrive have/has been in/at Kitty has been in HK for two days. leave have/has been away She has been away from home since Tuesday. borrow have/has kept She has kept this book since last week. join have/has been in have/has been a member of Simon has been a member of the Football Club since last year. marry have/has been married They have been married for 15 years. die have/has been dead The fish has been dead for some time. 常见短暂性动词用可延续性同义词或be+ adj.替换 Explanation Work in groups. Interview your groupmates using the questions below. Share the answers with the class. 4d How long have you ·known your best friend / that girl / ...? ·had your favourite toy / bag / ...? ·lived in this town / your neighbourhood / ...? Elaboration 现在完成时 1.现在完成时的 “未完成”用法 2.延续性动词与 非延续性动词 ①现在完成时+for+一段时间 ②现在完成时+since+表示过去的时间点 ③现在完成时+since+从句 ①含义 ②用法 ③非延续性动词转换为延续性动词的 方法：a．转化为“be+形容词或副词” b．转换为意思相同的延续性动词 Summary $