Unit 5 语法讲义 2026-2027学年外研版八年级英语上册

本讲义聚焦动词不定式作目的状语这一核心语法点，系统梳理to do、in order to、so as to三种形式的用法及位置规律，通过教材课文《Rules》中的真实例句搭建从基础认知到难点突破（与宾语补足语区分）的学习支架，帮助学生循序渐进掌握知识点。 该资料以单元主题“规则”为依托，用课文情境例句（如“I covered my ears in order to block the noise”）提升语言能力，通过“是否有宾语”“回答why或what”等方法辨析目的状语与宾补，培养思维品质。综合训练结合中考考法设计情境任务（写信），课中助力教师高效授课，课后帮助学生强化练习、查漏补缺，提升学习能力。

Unit 5 Play by the rules? 语法讲义 外研版（2022年版课程标准修订）· 八年级上册 语法板块：动词不定式作目的状语 Unit 5 的主题是「规则」：课文《Rules》里，「我」在晚高峰的火车上先后遭遇大声外放的女孩、气味浓烈的食物和踢座椅的男孩，忍无可忍之际看到墙上的标语，终于鼓起勇气站起身——I covered my ears in order to block the noise.／I covered my nose so as to reduce the smell.／And rules are there for us to follow! 这些句子集中展示了本单元的语法核心：动词不定式作目的状语。本讲义按教材附录（p131–132）讲清 to do、in order to、so as to 三种形式和它们的位置，辨清目的状语与宾语补足语，最后配综合训练。 一、基本形式：to do 作目的状语 教材的说明是：动词不定式可以在句中作目的状语，表示行为动作的目的，回答「做某事是为了什么」。作目的状语时，不定式既可以放在句尾，也可以放在句首。 【教材出处】教材附录 Guide to the language use p131（正文 Grammar rules ⇢ p131） The WWF is working hard to save all the animals. 世界自然基金会正在努力挽救所有的动物。 She practises every day to improve her singing skills. 她每天都在练习，以提高自己的歌唱技巧。 Dylan trained hard to improve his basketball skills. Dylan 刻苦训练以提高自己的篮球技术。 　也可以说：To improve his basketball skills, Dylan trained hard.（放在句首，后面加逗号） 课文《Rules》开篇两句就是最自然的目的状语（教材 p68，也是教材 p71 活动 5 例句 (a)(b)）： I got on the train to go home. 我上了火车回家。 I went to a quiet area in order to read. 我走到一个安静的区域去读书。 易错点睛 判断 to do 是不是目的状语，就问它能不能回答 why：I got on the train to go home.——为什么上火车？回家。能回答，就是目的状语。另外，句首的目的状语后面要加逗号：To improve his basketball skills, Dylan trained hard. ✓ 二、in order to 与 so as to 教材的说明是：除了直接使用 to do sth 之外，还可以使用 in order to do sth 和 so as to do sth 来表示行为动作的目的。 【教材出处】教材附录 p132 He's saving money in order to buy a new computer. 为了买一台新电脑，他正在攒钱。 Linda started work early so as to finish it by five. Linda 很早就开始工作，以便在五点前完成。 课文里「我」的一连串自救动作，把两种形式全用上了（教材 p69，含 p71 活动 5 例句 (c)）： I covered my ears in order to block the noise coming from Rock Girl. 我捂住耳朵，挡住「摇滚女孩」的噪音。 I covered my nose so as to reduce the smell coming from Mr Smelly Food. 我捂住鼻子，减少「重口味先生」的食物气味。 I turned around so as to see the other passengers' faces. 我转过身，想看看其他乘客的表情。 形式 位置 课文或教材例句 to do 句尾或句首 I got on the train to go home.／To improve…, Dylan trained hard. in order to do 句尾或句首 I went to a quiet area in order to read.／In order to catch the earliest train, Sally arrived before 6:00 am. so as to do 一般只放句尾 I covered my nose so as to reduce the smell.（课文） 否定目的 not 放 to 前 in order not to miss the train 以免错过火车（拓展） 易错点睛 so as to 一般不放在句首；句首的位置留给 to do 或 in order to do。误 So as to catch the bus, he ran.（考试不取）　正 In order to catch the bus, he ran. ✓。否定形式两个都成立：in order not to / so as not to。 中考考法 ① 单选考形式区分：______ catch the first bus, he got up early.（To / So as to 均可时优先 In order to，so as to 不放句首）；② 改写句是固定题型：People wear seat belts in cars. People want to stay safe on the road. → People wear seat belts in cars to stay safe on the road.（教材 p71 活动 6 原题）；③ 完成句子考 for sb to do（见下文课文金句）。 三、难点突破：目的状语还是宾语补足语 难点突破｜目的状语 vs 宾语补足语（跨单元串联 U4） 难点是什么｜I asked him to stop.（U4 宾补）和 I stood up to see better.（目的状语）外形几乎一样，都是「动词 + to do」，学生分不清成分，改错和填空时乱套。 学生为什么错｜两个结构共享 to do 这个外衣，但内部关系不同：宾补结构里 to do 是宾语的动作（him 去 stop），删掉宾语句子就不成立；目的状语是主句动作的「目的」，删掉后主句依然完整。 怎么判断（可教给学生的话）｜ (1) 看 to do 前面有没有「人」作宾语：有（asked him to stop）→ 往宾补方向判断。 (2) 问 to do 回答的是 what 还是 why：回答 why（为什么站起来？为了看得更清楚）→ 目的状语。 (3) 用 in order to 替换验证：能替换成 in order to 且句意不变 → 目的状语；宾补不能用 in order to 替换。 教材例证｜课文《Rules》把两种结构放在同一段里：I asked him to stop.（宾补：him 去停止，教材 p69）／I turned around so as to see the other passengers' faces.（目的：转身是为了看清脸，教材 p69） 当堂变式｜① He got up early to catch the first bus.（起早为了赶车 → 目的状语）② The teacher asked him to hand in the homework.（him 去交作业 → 宾补） 一句话纠偏｜目的状语回答 why、可换 in order to；宾补补的是宾语的动作、前面一定站着个宾语。 拓展 课文里还有一句漂亮的 for sb to do：And rules are there for us to follow! 规则就在那里，等着我们去遵守！（教材 p69）「for + 人 + to do」表示「该某人做某事」，是不定式的高级用法：It's time for us to set off.／Here are the books for you to read。中考完成句子偶见，认得即可。 四、综合训练（情境：给「知心姐姐」写一封信） 下面四组练习覆盖本讲义全部考点，总分 40 分。建议限时 25 分钟。 练习一　句子改写：用 to、in order to 或 so as to 连接两句（每小题 3 分，共 9 分） 1. People wear seat belts in cars. People want to stay safe on the road.（教材 p71 活动 6 原题） 2. Sally arrived at the train station before 6:00 am. She needed to catch the earliest train.（同上） 3. I listened carefully in maths class. I hope to improve my grades.（同上） 练习二　语篇填空：用括号中的笔记补全给 Story Aunt 的信（每空 2 分，共 10 分） （改编自教材 p71 活动 7，括号内为提示） Dear Story Aunt, 1 ________ (I'm writing, share a touching story). Yesterday, 2 ________ (I left my flat, go to work). However, I found my favourite flowerpot broken. 3 ________ (I picked up the pieces, clean up the mess). Then I saw a note from a boy. 4 ________ (he wrote the note, say sorry to me). His honesty made me respect him. I'm 5 ________ (sharing my story, spread some happiness). 练习三　单项选择（每小题 2 分，共 12 分） 1. He got up early ______ the first bus. 　A. catch　B. catching　C. to catch　D. caught 2. ______ get to school on time, Li Ming runs for twenty minutes every morning. 　A. So as to　B. In order to　C. In order that　D. / 3. She covered her eyes ______ the bright light. 　A. block　B. so as to block　C. so as not to block　D. blocks 4. The teacher raised her voice ______. 　A. make us hear　B. to make us hear　C. for making us hear　D. made us hear 5. Rules are there ______. 　A. for us to follow　B. for us follow　C. to us for following　D. us to follow 6. —______ did you go to the quiet area? —______ read in peace. 　A. What; For　B. Why; To　C. How; To　D. When; For 练习四　根据中文提示完成句子（每小题 3 分，共 9 分） 1. 我捂住鼻子，为了减少那股气味。（so as to）I ________________________________ the smell. 2. 为了赶上最早的一班车，Sally 早上 6 点前就到了车站。（in order to，放句首）________________________, Sally arrived at the train station before 6:00 am. 3. 我们每天练习，以提高歌唱技巧。（to do）We ________________________________ our singing skills. 参考答案与解析 练习一　1. People wear seat belts in cars to stay safe on the road.　2. Sally arrived at the train station before 6:00 am to catch（in order to catch）the earliest train.　3. I listened carefully in maths class to improve（in order to improve）my grades. 练习二　1. I'm writing to share a touching story　2. I left my flat to go to work　3. I picked up the pieces to clean up the mess　4. He wrote the note to say sorry to me　5. sharing my story to spread some happiness 解析：每个空都要求把「做某事」变成目的状语；第 2 空两个动作连用（left…to go…）；第 5 空 sharing 与 to spread 连用，前者接在 I'm 后构成进行时，后者作目的状语。 练习三　1. C　2. B　3. B　4. B　5. A　6. B 解析：第 1 题目的状语用 to catch；第 2 题句首只能用 In order to（so as to 不放句首），选 B；第 3 题是「捂眼挡光」，肯定目的用 so as to block；第 4 题 raise voice 的目的「让我们听见」，用 to make us hear；第 5 题 for us to follow 固定结构；第 6 题答目的用 To read in peace（= In order to read in peace）。 练习四　1. I covered my nose so as to reduce the smell.　2. In order to catch the earliest train　3. We practise every day to improve our singing skills. 自查：① so as to 没放句首吧？② to do 能换成 in order to 吗？能就是目的状语；③ not 紧贴在 to 前了吗？ 五、速记口诀 目的状语 to do 挑，句尾句首都能靠。 in order to 最全能，so as to 别往前跑。 否定 not 贴 to 前：so as not to be late 记住就好。 回答 why 的是目的，宾语身后才叫宾补。 学习小建议：《Rules》这篇课文是不定式目的状语的「天然例句库」，从 I got on the train to go home 到 rules are there for us to follow 一共七处。把它朗读两遍并挑三句仿写，这个考点就长在语感里了。 外研版八年级上册 Unit 5 语法讲义（Play by the rules?） 第 页 / 共 页 学科网（北京）股份有限公司 $