Unit 4 Grammar 讲义 2026-2027学年英语译林版八年级上册

Unit 4 Hands-on fun　Grammar 课时基本信息 课　　题 Unit 4 Hands-on fun — Grammar 课　　型 语法课（第三课时·45分钟） 年　　级 八年级上册 版　　本 译林版（2024）英语八年级上册 教学重难点 【教学重点】 掌握祈使句的基本结构：肯定（Do.../Be.../Let's...）、否定（Don't.../Never...）、委婉（please）、提议（Let's...）,掌握 should 与 had better 提建议的用法：两者均接动词原形，had better 语气更强；否定形式 had better not do 【教学难点】 had better not do 的正确形式（不可写成 hadn't better）；Don't be... 的 be 动词否定,根据语境恰当区分 should（温和建议）与 had better（强语气/后果暗示） 词汇速览 Don't do / Don't be /dəʊnt/ 不要做/不要成为（祈使句否定：Don't+动词原形；be 动词否定为 Don't be...——Don't touch the wet paint! 请勿触摸未干的油漆！Don't be rude to the guests! 别对客人无礼！） should / shouldn't /ʃʊd/ 应该/不应该（情态动词，后接动词原形，语气较温和——You should mix the paint well. 你应该把油漆调匀。You shouldn't go too fast. 你不应该太快。） had better (not) do /hæd ˈbetə(r)/ 最好（不要）做（'d better = had better；语气比 should 强，暗示「不做会有麻烦」；否定 had better not do，不可写 hadn't better——You'd better leave now, or you'll miss the last bus. 你最好现在就走，否则赶不上末班车。） Let's do /lets/ 我们……吧（Let us 缩写，表提议集体行动——Let's put the pieces of wood together. 我们把木块拼起来吧。Let's take a short break. 我们休息一会儿吧。） （一）导入 · 让别人做与不做 【过渡语】动手做 DIY，最常说的就是「这么干」「别那么干」——今天学的语法全在这两句话里。 Free talk：What do you say when you want someone to do, or not to do, something?（想让别人做某事/不做某事时，你会说什么？） 看标志牌猜含义：Can you guess what these signs mean? Where can you see these signs? How do we say them in English?（这些标志什么意思？在哪里见过？英语怎么说？）——如 Don't touch!／Keep off the grass! 等。 DIY 话题预热：Do you like DIY? What have you made by hand?（你喜欢 DIY 吗？动手做过什么？） 【提示框】 标志牌是祈使句的「天然教科书」——Stop!／Don't park!／Keep quiet! 全是动词原形开头的指令。 （二）情境铺垫 · 给朋友的两条建议 Your friend is painting a bird box. What advice do you give? Give your friend two pieces of advice.（朋友在刷鸟箱，给他两条建议。）Which sounds stronger? What should your friend NOT do?（哪条语气更强？朋友不该做什么？） 两条建议的设计：一条用 should（You should clean the box first.），一条用 had better（You'd better not get too much paint on the brush.）——语气的强弱差别就是本课第二个语法点的引子。 （三）对话观察 · 装书架四句 Millie and Andy are trying to put together a bookshelf. Read their conversation and pay attention to the parts in bold：Andy: Let's put the pieces of wood together. Please hand the tools to me.（我们把这些木块拼起来吧。请把工具递给我）Millie: OK. Here you are. What else can I do? Suzy: Look for the chalk mark on the top of each piece. Make sure pieces of the same size are in the same group. Don't mix them up!（找每块木块顶端的粉笔标记。确保同尺寸的在同组。别把它们弄混了！） 观察四句的四个「开关」：Let's（提议）、Please（礼貌）、动词原形 Look for/Make sure（指令）、Don't（禁止）。 【知识点】 ▶一段对话四种祈使句：Let's put...（提议集体做）、Please hand...（礼貌请求）、Look for.../Make sure...（直接指令）、Don't mix them up!（禁止）——祈使句不是一种句式，是一个「语气家族」。 Millie 与 Andy 装书架对话页 （四）规则归纳 · 祈使句四条 Imperative sentences 归纳：①We start a sentence with the base form of a verb when we want to tell people what to do.（想告诉别人做什么→动词原形开头）；②We add "don't" before a verb when we want to tell people not to do something.（想让别人不做→动词前加 don't）；③We often add "please" in a sentence to make an instruction more polite.（加 please 更礼貌）；④We can use "let's" when we want to suggest doing something together.（let's 提议一起做）。 语气谱系：祈使句表达叮嘱、劝告、希望、禁止、请求或命令——Turn off the lights before you leave.（叮嘱/命令）Enjoy your meal!（希望/祝愿）Keep your voice down in the library.（劝告）Don't touch the wet paint!（禁止/警告）。主语通常为第二人称 you，一般省略。 【知识点】 ▶四条规则一句记：动词原形开头、don't 表否定、please 表礼貌、let's 表提议——主语 you 藏在句子里被省略，这是祈使句区别于陈述句的第一特征。 【提示框】 同一句祈使句语气可变：Turn off the lights.（命令）→Please turn off the lights.（礼貌请求）→Don't turn off the lights!（禁止）——加什么词，语气就往哪边走。 （五）肯定结构 · 三种句式 【过渡语】肯定怎么「起头」？三种句式各有开场白。 ①Be+表语（名词或形容词）：Be patient with the elderly. 对老人要耐心（Be+形容词，劝告/叮嘱）；Be a good listener. 做一个善于倾听的人（Be+名词短语，希望/建议）。②Let+宾语+动词原形：Let her explain the situation. 让她解释一下情况（请求/允许）；Let's take a short break. 我们休息一会儿吧（Let's=Let us，常用于集体行动）。 ③动词原形(+宾语)(+其他)：Pass me the salt. 把盐递给我（双宾语请求）；Drive carefully! 开车小心（动词原形+副词，叮嘱/警告）。please 位置规则：句首其后不用逗号（Please pass me the ball.）；句末其前通常加逗号（Pass me the ball, please.）——两句等义。 【知识点】 ▶三种开头=三类动词：Be（状态）、Let（让/提议）、动作动词（做）——「别忘 be 动词也能开头」是最易漏的一条；please 的逗号规则：句首无逗号、句末前加逗号。 （六）否定结构 · 三种句式 ①Don't+be+表语：Don't be rude to the guests! 别对客人无礼（Don't+be+形容词）；Don't be a stranger. 别生分了（Don't+be+名词）——be 动词的否定形式为 Don't be...。②Don't let+宾语+动词原形（口语常用，语气直接）／Let+宾语+not+动词原形（书面正式，语气庄重）：Don't let the children play near the road.＝Let the children not play near the road. 别让孩子们在路边玩耍。 ③Don't/Never+动词原形(+宾语)(+其他)：Don't touch the wet paint. 别碰未干的油漆（即时禁止/提醒）；Never leave your luggage unattended. 切勿让行李无人看管（Never 表严格禁令/安全警示）。 【知识点】 ▶否定三式记两头：日常口语 Don't 通吃（含 Don't be）；Never 顶格禁令用于安全警示——Don't let 与 Let...not 是同义的两副面孔（口语 vs 书面）。 【提示框】 检测词形第 3 空 Be patient：祈使句肯定用 Be 原形开头，别写成 Don't be——先看题干是劝告还是禁止。 （七）闪卡七空 · 制作说明书 【过渡语】规则在手——Millie 正教同学们做单词闪卡，七句「制作说明」等你补全。 Millie is teaching her classmates how to make flashcards. Complete the sentences with the words in the box (cut/draw/give/keep/look/try/write)： (1) Cut cards out of pieces of paper with a pair of scissors.（用剪刀把纸剪成卡片）(2) Write some words or a sentence on each card.（每张卡上写些单词或一个句子）(3) Draw a picture to show the words or sentence on the other side of the card.（在卡片另一面画图示意单词或句子）(4) Look at the picture and (5) try to say what is on the other side.（看图并尝试说出另一面的内容）(6) Please don't give up.（请别放弃）(7) Keep trying and you will find you can remember things better.（坚持尝试，你会发现你能记得更牢） 【知识点】 ▶七空三种句式轮换：Cut/Write/Draw/Look（动词原形指令）→Please don't give up（Don't 否定+惯用语 give up 放弃）→Keep trying（Keep doing 坚持做）——说明书=祈使句串烧，制作步骤一句一令。 【提示框】 第 5 空 try to say（尝试说出）与第 7 空 Keep trying（坚持尝试）呼应——try 是本课的「双重身份」词：try to do 尝试做、Keep trying 别放弃。 闪卡制作七空页 （八）输出 · 升降课桌说明书 There is a new type of desk at your school. You can change the height of the desk by pressing a button. Write some sentences, using the grammar above, to teach your classmates how to use the desk.（学校有一新款课桌，按按钮可调高度。用本课语法写几句教同学使用。） 示例骨架：Press the button to change the height.（按按钮调高度）Don't put your hands under the desktop when you press the button.（按按钮时别把手放在桌面下）Be careful with the sharp corners.（小心尖锐的边角）Let's keep the desk clean after using it.（用完把桌子保持整洁吧） （九）对话观察 · 刷鸟箱建议 【过渡语】第二个语法点登场——Suzy 和妈妈刷鸟箱，听听妈妈怎么给建议。 Suzy and her mum are trying to paint a bird box. Read their conversation and pay attention to the parts in bold：Mum: Here's the paint. We'd better clean the bird box first.（我们最好先把鸟箱清洗一下）Suzy: OK, I'll help you. Mum: Now you should mix the paint well. Then put the brush into the paint. You'd better not get too much paint on the brush.（你应该把油漆调匀。刷子上最好不要蘸太多漆）Suzy: Is this OK? Mum: Yes. Move the brush up and down slowly like me. You shouldn't go too fast, Suzy.（像我一样慢慢上下移动刷子。你不应该太快） 四句建议两对正负：'d better clean（肯定）↔'d better not get（否定）；should mix（肯定）↔shouldn't go too fast（否定）。 Suzy 与妈妈刷鸟箱对话页 （十）归纳对比 · should vs had better We use should and had better when giving advice and telling people what we think is best or the right thing to do.（提建议、告诉别人什么是最好的或该做的事时用 should 和 had better。）Tip：'d better = had better；shouldn't = should not；The tone of had better is stronger than should.（had better 语气比 should 强。）两者都是情态动词，后接动词原形，没有人称和数的变化。 对比表四栏：语气强度——had better 强（接近警告/催促）vs should 弱（友好建议/期望）；隐含含义——had better「不做会有麻烦」vs should「这样做是好的/对的」；适用场景——had better 紧急情况/具体风险/严重后果 vs should 日常建议/道德义务/普遍真理；否定形式——had better not do vs should not/shouldn't do。 例句对比：You had better leave now, or you'll miss the last bus. 你最好现在就走，否则就赶不上末班车了（隐含后果：错过车）vs You should get more sleep if you want to stay healthy. 如果想保持健康，就应该多睡会儿（温和建议）。 【知识点】 ▶一张表定用法：句子里有「后果暗示」（or you'll...）用 had better；只是「为你好」的日常提醒用 should——否定的坑只有一个：had better not do（不可写 hadn't better）。 should 与 had better 对比表页 （十一）Suzy 七句 · DIY 建议 Suzy is giving DIY advice to her classmates. Help Suzy make sentences with should (not) or had better (not)：1 There are many useful books about DIY.→You should/had better read them slowly and carefully.（慢慢仔细地读）2 DIY is not always easy.→You should/had better practise more.（多练习）3 Instructions are important.→You should/had better not begin your work without reading them.（不读说明书别开工） 4 Scissors can be dangerous.→You should/had better not play with them when you do DIY jobs.（别拿剪刀玩）5 Sometimes it takes time to do a DIY job.→You should/had better be patient.（要有耐心）6 Glue can hurt your skin and eyes.→You should/had better be careful when you use it.（用胶水要小心）7 （学更多）→You should/had better join a DIY club to learn more about it.（加入 DIY 社团） 【知识点】 ▶七句按「语境风险」选词：剪刀伤人、胶水伤眼——具体风险→had better not（更强）；多练、耐心、入社团——一般建议→should（温和）；「不读说明书别开工」后果严重→had better not 首选。 【提示框】 第 3、4 空的 not 位置：had better not do／should not do——not 都放在情态动词后、动词原形前，千万别写成 hadn't better。 （十二）语言点精讲 · 三组深化 【过渡语】练完了再回头精讲——三组语言点把两大语法点钉死。 ①祈使句肯定：以动词原形开头，用于表达指令、建议、请求或操作步骤；在 DIY 语境中常用来描述制作过程中的具体动作；语气直接，主语 you 被省略。例：Cut the paper into small pieces. 把纸剪成小片。／Mix the paint and water well. 把油漆和水充分混合。 ②祈使句否定：结构为「Don't+动词原形」，用于表示禁止、警告或劝阻；在安全提示和操作规范中极为高频，强调「不该做某事」；注意 be 动词的否定形式为 Don't be...。例：Don't use scissors without adult help. 没有大人帮助不要用剪刀。／Don't touch the wet paint. 不要碰未干的油漆。 ③should 与 had better：should 表示一般性建议或义务，语气较温和，意为「应该」，否定形式为 shouldn't；had better 语气比 should 更强，带有「如果不这样做可能会有不良后果」的暗示，意为「最好……」，否定形式为 had better not+动词原形（易错点：不可写成 hadn't better）。例：You should keep the workspace clean. 你应该保持工作区域整洁。／You'd better not mix chemicals randomly. 你最好不要随意混合化学品。 【知识点】 ▶三组钉成三句话：祈使句=动词原形开头（you 省略）+Don't 否定+please/Let's 缓冲；should 温和建议、had better 强语气带后果暗示；否定都在情态动词后加 not（had better not do，不可 hadn't better）——检测两道选择与五道词形全部落在这三句话上。 【提示框】 检测第 1 题思维路径：The glue can hurt your skin（胶水伤皮肤=具体风险）→You shouldn't play with it（A）——hadn't better 是错误形式直接排除 D；第 2 题 or you will miss the last bus（后果暗示）→had better（B）。 （十三）随堂检测 限时独立完成随堂检测（本课语法），完成后同桌互批，逐题核对订正。 一、1. A　2. B　二、3. don't mix　4. should　5. Be　6. not leave　7. try 一、单项选择 1. — The glue can hurt your skin. You __________ play with it. A. shouldn't　B. don't　C. not　D. hadn't better 2. You __________ leave now, or you will miss the last bus. A. should　B. had better　C. please　D. let's 二、用括号内单词的正确形式填空 3. Please __________ (not mix) the chemicals randomly; it is dangerous. 4. You __________ (should) read the instructions carefully before starting. 5. __________ (be) patient with the elderly when you help them. 6. You'd better __________ (not leave) the wet paint unattended. 7. Let's __________ (try) to make flashcards to remember words better. （十四）小结与作业 Summary 两条：①祈使句——以动词原形开头表指令（Cut...），否定用 Don't+动词原形（Don't touch...），委婉加 Please，提议用 Let's。②Should vs. Had better——两者均接动词原形表建议；should 语气较温和；had better 语气更强，暗示不做的后果，其否定形式为 had better not do。 Homework：Review——Memorize the structures of imperative sentences and the differences between "should" and "had better". 背记祈使句结构与 should/had better 的区别。Preview——Preview the next lesson. 预习下一课。 【提示框】 背记自查双句：祈使句四种开头（Do/Be/Let's/Don't）各默一句；had better not do 写五遍防 hadn't better——拼写级错误靠重复焊死。 语言点归纳 课堂总结 本课为单元语法课（第三课时）：导入——Free talk：What do you say when you want someone to do, or not to do, something?（想让别人做/不做某事时怎么说？）看标志牌猜含义（Where can you see these signs?）；DIY 话题：Your friend is painting a bird box. What advice do you give?——给两条建议，一条用 should、一条用 had better，Which sounds stronger?（哪个语气更强？）Millie 与 Andy 装书架对话：Let's put the pieces of wood together. Please hand the tools to me.／Look for the chalk mark on the top of each piece. Make sure pieces of the same size are in the same group. Don't mix them up!（别把它们弄混了！）归纳祈使句四条：We start a sentence with the base form of a verb when we want to tell people what to do.（动词原形开头表指令）；We add "don't" before a verb when we want to tell people not to do something.（don't 表否定）；We often add "please" to make an instruction more polite.（please 礼貌）；We can use "let's" when we want to suggest doing something together.（let's 提议一起做）。祈使句详解：表达叮嘱、劝告、希望、禁止、请求或命令，以动词原形开头，主语通常为第二人称 you，一般省略——Turn off the lights before you leave.（叮嘱）／Enjoy your meal!（祝愿）／Keep your voice down in the library.（劝告）／Don't touch the wet paint!（禁止）。肯定结构三种：①Be+表语——Be patient with the elderly. 对老人要耐心；Be a good listener. 做善于倾听的人；②Let+宾语+动词原形——Let her explain the situation.（请求/允许）；Let's take a short break.（提议集体行动）；③动词原形(+宾语)(+其他)——Pass me the salt.（双宾语请求）；Drive carefully!（叮嘱/警告）。please 位置规则：句首其后不用逗号，句末前通常加逗号——Please pass me the ball. = Pass me the ball, please. 否定结构三种：①Don't be+表语——Don't be rude to the guests!／Don't be a stranger. 别生分了；②Don't let+宾语+动词原形（口语常用）／Let+宾语+not+动词原形（书面正式）——Don't let the children play near the road.＝Let the children not play near the road.；③Don't/Never+动词原形——Don't touch the wet paint.（即时禁止）；Never leave your luggage unattended.（严格禁令/安全警示，切勿让行李无人看管）。Millie 闪卡七空：Cut cards out of pieces of paper with a pair of scissors.（用剪刀把纸剪成卡片）Write some words or a sentence on each card.（每张卡上写单词或句子）Draw a picture to show the words or sentence on the other side of the card.（另一面画图示意）Look at the picture and try to say what is on the other side.（看图尝试说出另一面内容）Please don't give up.（请别放弃）Keep trying and you will find you can remember things better.（坚持尝试，你会发现记得更牢）。输出任务：学校有新课桌，按按钮可调高度——用祈使句写使用说明。Suzy 与妈妈刷鸟箱对话：We'd better clean the bird box first.（最好先清洗）You should mix the paint well.（应该把油漆调匀）You'd better not get too much paint on the brush.（刷子上别蘸太多漆）You shouldn't go too fast.（不应该刷太快）。用法归纳：We use should and had better when giving advice and telling people what we think is best or the right thing to do.（should 与 had better 用于提建议）；Tip：'d better = had better；shouldn't = should not；The tone of had better is stronger than should.（had better 语气更强）。两者都是情态动词，后接动词原形，没有人称和数的变化。核心区别四栏：语气强度——had better 强（接近警告/催促）、should 弱（友好建议/期望）；隐含含义——had better「不做会有麻烦」、should「这样做是好的/对的」；适用场景——had better 紧急情况/具体风险/严重后果、should 日常建议/道德义务/普遍真理；否定形式——had better not do、should not/shouldn't do。例句对比：You had better leave now, or you'll miss the last bus.（隐含后果：错过车）vs You should get more sleep if you want to stay healthy.（温和建议）。Suzy 七句 DIY 建议：1 You should/had better read them slowly and carefully.（慢慢仔细读说明书）2 You should/had better practise more.（多练习）3 You should/had better not begin your work without reading them.（不读说明书别开工）4 You should/had better not play with them when you do DIY jobs.（做 DIY 时别玩剪刀）5 You should/had better be patient.（要有耐心）6 You should/had better be careful when you use it.（用胶水要小心）7 You should/had better join a DIY club to learn more about it.（加入 DIY 社团学更多）。语言点三组：祈使句肯定（动词原形开头表指令，主语 you 省略）；Don't 否定（Don't+动词原形，be 动词否定为 Don't be...）；should/had better（语气差异与否定形式，易错点：不可写成 hadn't better）。随堂检测：选择两题＋词形五题。 学科网（北京）股份有限公司 $