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

译林版八年级英语下册 Unit 1 Past and present Grammar 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 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 主语+have/has助动词 + done(过去分词)+其他 Present perfect tense 现在完成时的基本构成 ： I/We/You/They + have + done(过去分词）+其它。 He/She/It + has + done(过去分词）+其它。 e.g. They ______________ their homework. (finish） He ______________his homework. （finish) have finished has finished 现在完成时的一般疑问句 Have you arrived？ Has she arrived？ Have/Has 主语 Have Tom and Jane arrived？ 肯定句的主语和have/has调换位置变一般疑问句 过去分词 Yes, I have. / No, I haven’t. Yes, she has. / No, she hasn’t. Yes, they have. / No, they have’t. 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 过去持续到现在的动作或状态 过去的行为对现在产生影响 动作已经发生0-多次 结构: 标志词: 主语+have/has done+其它 already,ever,just,never,recently,yet,before since,for,in the past years, over/during the years, in recent years, so far When to use? Sentences 现在完成时与for和since的用法 I have been here for 10 days. I have been here since 10 days ago. I have been here since I was born. for+一段时间 since+时间点（年月周日时） I have been here since January 10th. since+时间段+ago since+一般过去时从句 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. 现在完成时的肯定句、否定句与一般疑问句 肯定句 否定句 一般疑问句 肯定回答 否定回答 sb have/has done (sth). sb have/has not done (sth). Have/Has sb arrived? Yes, sb have/has. No, sb haven’t/hasn’t . I have We have You have They have He/She/It has have not has not =I’ve =We’ve =You’ve =They’ve =He’s/She’s/It’s =haven’t =hasn’t 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? What are the changes in your hometown? Housing We used to live in small houses, but most families have moved into new buildings. What are the changes in your hometown? Culture Environment Industry The quality of life Transport Grammar Focus 1: Usage Use 1: Definition An action started in the past and continues to the present. Key Markers Often used with:for, since Examples Hehas livedheresince2010. Ihave studiedEnglishfor5 years. 1.7.2013 Now let's dive into the grammar rules. The first main usage is to describe an action that started in the past and is still happening now. We often use time expressions like "for" (to show a period of time) and "since" (to show a starting point in time) with this usage. ‹#› Grammar Focus 2: Usage Core Concept An action happened in the past and has a connection with the present. (The exact time is not mentioned.) Example 1: Consequence Ihave lostmy key. (Result: I can't open the door now.) Example 2: Experience Shehas seenthis movie. (Result: She knows the story now.) 1.7.2013 The second usage is to talk about a past action that has a result or connection to the present moment. We don't usually say when the action happened. For example, if I say "I have lost my key," the important thing is the present result: I don't have my key now and can't open the door. ‹#› Pair work A: Hi! Long time no see. I heard you went back to your hometown last month. How was the visit? B: Oh, it’s amazing!_____________________________________________. A: Wow, that’s great. My hometown has changed a lot too.______________ _____________________________________________________________. B: Really? ____________________________________________________. A: That’s cool. In my hometown, __________________________________. B: Times really have changed. I think our hometowns will become even better in the future. A: I agree. I can’t wait to go back during the holiday to see more changes! Present perfect tense Form the past participles of verbs When to use the present perfect tense Form the sentence structures Time adverbials have/has + done have/has+ not + done Have/Has + subject+ done...? Yes, subject + have/has. No, subject + haven’t/hasn’t. present the present Grammar Focus: Structure Positive Sentences I / You / We / Theyhave+ past participle ... He / She / Ithas+ past participle ... Negative Sentences ...have not (haven't)+ past participle ... ...has not (hasn't)+ past participle ... Questions HaveI / you / we / they + past participle ...? Hashe / she / it + past participle ...? Short Answers Yes, I/you/we/theyhave. / No, ...haven't. Yes, he/she/ithas. / No, ...hasn't. 1.7.2013 Now let's look at the basic structure. For positive sentences, we use "have" or "has" plus the past participle. For negatives, we add "not" after "have" or "has". For questions, we put "have" or "has" at the beginning of the sentence. Short answers are also formed with "have" or "has". ‹#› Time adverbials ❀since + a specific time/+ a sentence in the simple past tense ❀ for + a period of time ❀ over / in the (past / last) years “在(过去的)这几年间” ❀ so far, up to now, until / till now “到目前为止” ❀ already “己经” “还(没)”“己经” ❀ yet ❀ ever “曾经” ❀ never “从未” ❀ just “刚刚” ❀ recently “最近” ❀ before “以前” ❀ time adverbials indicating the number of times 表示次数 Grammar Focus: Past Participle Regular Verbs (规则动词) Rule: Add-ed(like the simple past) finish - finished change - changed carry - carried stop - stopped Irregular Verbs (不规则动词) Rule: No fixed rule (need to memorize) come - come hold - held buy - bought see - seen be - been fall - fallen 1.7.2013 The key part of the Present Perfect Tense is the past participle. For regular verbs, it's easy: we just add "-ed", the same as the simple past tense. But for irregular verbs, the past participle has different forms, and we need to memorize them one by one. Let's review some common ones. ‹#› Practice A: Fill in the blanks 1. Sunshine Town ______________ (change) a lot over the years. 2. The government ______________ (turn) part of the town centre into a new park. 3. Recently, the air in our town ______________ (improve) a lot. 4. Some people in the countryside ______________ already ______________ (move) to new buildings. 5. Last year, the government ______________ (build) an art museum. 6. I ______________ (not visit) the museum yet. 1.7.2013 Now it's practice time! Let's start with Exercise A. Please complete the sentences about the changes in Sunshine Town using the correct form of the verbs in brackets. You have 3 minutes to finish it by yourself. ‹#› Compulsory homework: (1) Review the grammar rules. (2) Write an article about the changes in your hometown, using the present perfect tense. Optional homework: Interview your classmates and know more about the changes in their hometown. Homework Thanks for your listening! $