Unit 8 Making a Difference单元语法专题-2025-2026学年人教版八年级下册英语

Unit 8 Making a Difference 单元语法专题 一、核心语法 —— 知识点精讲（必背） 1. 现在完成时（核心必考，表志愿经历与影响） 用法：本单元重点考查现在完成时表“过去的志愿服务经历、已完成的公益行动或善意行为带来的影响”，即“曾经参与志愿活动、完成公益任务或通过帮助他人获得成长”，贴合单元“传递善意、创造改变”主题，是描述志愿经历、分享帮助他人收获的核心语法，也是书面表达和对话的高频考点。 标志词：ever（曾经）、never（从未）、already（已经，多用于肯定句）、yet（还；尚未，多用于否定句和疑问句末尾）、just（刚刚）、before（以前）、recently（最近）、since（自从……以来）、for+一段时间（持续多久） 结构： 肯定：主语（三单） + has + 动词过去分词 + 其他；主语（非三单） + have + 动词过去分词 + 其他 否定：主语（三单） + hasn’t + 动词过去分词 + 其他；主语（非三单） + haven’t + 动词过去分词 + 其他 疑问：Has + 主语（三单） + 动词过去分词 + 其他？ / Have + 主语（非三单） + 动词过去分词 + 其他？（回答：Yes, 主语 + have/has. / No, 主语 + haven’t/hasn’t.） 本单元核心动词过去分词（必考，贴合志愿主题）： volunteer → volunteered（志愿）、donate → donated（捐赠）、encourage → encouraged（鼓励）、organize → organized（组织）、cheer → cheered（使高兴）、raise → raised（筹集）、realize → realized（意识到）、help → helped（帮助） 例句（贴合单元话题）： ① I have ever volunteered in a community to help old people cross the road.（非三单肯定句：我曾经在社区做过志愿者，帮助老人过马路。） ② She hasn’t donated her old clothes to the poor yet.（三单否定句：她还没有把旧衣服捐赠给穷人。） ③ —Has he organized any charity activities at school? —No, he hasn’t. He plans to do it next month.（三单疑问句及回答：他在学校组织过慈善活动吗？没有，他计划下个月组织。） 2. 定语从句（重点必考，修饰志愿相关名词） 用法：用于修饰“志愿服务、善意行为”相关的名词（如volunteer activity, charity sale, homeless people, kind girl, volunteer work等），补充说明这些名词的特征、用途或相关情况，贴合单元“描述志愿活动、帮助对象、善意行为”的核心需求，是句型转换和书面表达的重点。 引导词：that/which（修饰事物，本单元主要修饰志愿类事物）、who（修饰人，本单元主要修饰志愿者、帮助对象等）；可省略的情况：当引导词在从句中作宾语时。 结构： 主句 + 定语从句（先行词<志愿类名词/人> + that/which/who + 从句谓语 + 其他） 常见搭配（贴合本单元词汇）： 1. a volunteer activity that/which helps homeless people（一个帮助无家可归者的志愿活动） 2. a kind girl who often helps sick children（一个经常帮助生病孩子的善良女孩） 3. a charity sale that/which raises money for the poor（一场为穷人筹集资金的慈善义卖） 4. volunteer work that/which brings us happiness（带给我们快乐的志愿工作） 例句（贴合单元话题）： ① This is a volunteer activity that/which was organized by our class last week.（定语从句修饰volunteer activity：这是我们班上周组织的一场志愿活动。） ② The homeless boy who we helped yesterday has found a new home.（定语从句修饰homeless boy：我们昨天帮助的那个无家可归的男孩已经找到了新家。） ③ The charity sale that/which we took part in raised a lot of money.（引导词作宾语，可省略：我们参与的那场慈善义卖筹集了很多钱。） 3. 情态动词should/could（表建议与请求，重点必考） 用法：本单元用于“针对志愿服务提出建议、请求他人参与志愿活动或提供帮助”，should语气较正式，表“应该”；could语气委婉，表“可以、能够”，贴合单元“倡导善意、参与志愿”的主题，是口语对话和书面表达的高频考点，也是易错点。 标志词：should（应该）、could（可以、能够）、advise（建议）、suggest（建议）、ask（请求） 结构（无人称和数的变化）： 肯定建议/请求：主语 + should + 动词原形 + 其他（应该做某事）；主语 + could + 动词原形 + 其他（可以做某事） 否定建议：主语 + should + not（shouldn’t） + 动词原形 + 其他（不应该做某事） 常见搭配（贴合本单元词汇）： 1. should volunteer our time to help people in need（应该自愿花时间帮助有需要的人） 2. could donate old books and clothes to poor children（可以把旧书和衣服捐赠给贫困儿童） 3. should cheer up sick children with funny stories（应该用有趣的故事让生病的孩子开心起来） 4. could help organize a charity activity at school（可以帮忙在学校组织一场慈善活动） 例句（贴合单元话题）： ① We should make an effort to help homeless people live a better life.（肯定建议：我们应该努力帮助无家可归者过上更好的生活。） ② You shouldn’t give up helping others even when you are busy.（否定建议：即使你很忙，也不应该放弃帮助别人。） ③ Could you help me cheer up the sick children in the hospital?（请求：你能帮我让医院里生病的孩子开心起来吗？） 4. 介词短语（表方式/目的，重点必考） 用法：用于描述志愿服务的方式、手段或目的，是修饰志愿行为、表达善意目的的核心补充语法，常与定语从句、陈述句结合使用，贴合单元“参与志愿、传递善意”的需求，也是书面表达的得分点。 核心介词及短语（贴合本单元词汇）： by（通过……方式）、with（用；以）、for（为了……）、in（在……里面）、by doing small kind things（通过做小事）、with kindness（用善意）、for the poor（为了穷人）、in the community（在社区里） 结构：介词短语可位于句首、句中或句末，作状语或定语 例句（贴合单元话题）： ① We can make a difference to the world by doing small kind things every day.（作状语，表方式：我们可以通过每天做小事来改变世界。） ② The volunteer with a warm smile is helping the old man carry things.（作定语，修饰volunteer：那个带着温暖笑容的志愿者正在帮老人搬东西。） ③ We organized a charity sale for the sick children in the hospital.（作状语，表目的：我们为医院里生病的孩子组织了一场慈善义卖。） 5. 志愿类常用句型（易错重点） 用法：结合本单元核心语法，用于询问、描述志愿场景、志愿经历及提出建议、请求，是口语对话和书面表达的核心句型，贴合“志愿服务、传递善意”的交流场景。 常用句型（必考）： 1. —Have you ever volunteered to help people in need? —Yes, I have. / No, I haven’t.（询问志愿经历） 2. This is a charity activity that helps the poor live a better life.（描述慈善活动+定语从句） 3. We should donate our old things to the poor instead of throwing them away.（提出建议+介词短语） 4. Could you tell me how to make a difference by doing volunteer work?（请求建议+介词短语） 6. 易错点辨析（贴合本单元语法） • 现在完成时与一般过去时的区别：现在完成时（have/has + 过去分词）表“过去的志愿经历对现在的影响”，不与具体过去时间（如yesterday, last week）连用；一般过去时（动词过去式）表“过去发生的具体志愿动作”，常与具体过去时间连用，如：I have volunteered in the community.（现在完成时，强调“有过社区志愿”的经历）/ I volunteered in the community last Saturday.（一般过去时，强调“上周六在社区做志愿”的具体动作） • 定语从句中that, which与who的区别：that可修饰人或事物，which只能修饰事物，who只能修饰人；本单元中，修饰志愿活动、慈善义卖等事物用that/which，修饰志愿者、帮助对象等人用who，如：The volunteer who helped me is my classmate.（修饰人，用who）/ The activity that we joined was meaningful.（修饰事物，用that） • should与could的区别：should表“建议”，语气较正式，强调“应该做”，有一定的必要性；could表“建议或请求”，语气更委婉，强调“可以做”，更具灵活性，如：You should help the old cross the road.（正式建议，强调责任）/ Could you help the old cross the road?（委婉请求，语气柔和） • 介词by与for的区别：by后接“志愿方式、手段”（动名词），贴合志愿场景；for后接“帮助对象、目的”，如：We help the poor by donating food.（通过捐赠食物，方式）/ We donate food for the poor.（为了穷人，目的） 二、核心语法 —— 专项练习题（基础 + 提高） 一、用所给动词的正确形式填空 1. My classmates and I __________ (volunteer) in the community twice since last month. 2. This is a charity sale that __________ (raise) money for the sick children in hospital. 3. —__________ you ever __________ (donate) your old clothes to the poor? —No, I haven’t. I plan to do it tomorrow. 4. We __________ (should) cheer up the homeless people to make them feel warm. 5. They __________ (not organize) any volunteer activities before; it’s their first time to plan one. 6. Our teacher __________ (encourage) us to make a difference with small kind actions last week. 7. You __________ (should not) refuse to help others when they are in trouble. 8. We __________ (already finish) donating books to the children in poor areas. 9. The volunteer work that we __________ (do) yesterday made us feel proud. 10. She __________ (realize) the importance of helping others since she joined the volunteer group. 二、单项选择 ( ) 1. —Have you ever met a kind person ______ often helps homeless animals? —Yes, she is my deskmate. A. who B. that C. which ( ) 2. This is the most meaningful volunteer activity ______ I have ever taken part in. A. which B. that C. who ( ) 3. —______ I donate my old toys to the children’s home? —Yes, you should. It’s very kind of you. A. Could B. Should C. Have ( ) 4. He ______ a lot of money for the poor before, so he is respected by everyone. A. raises B. raised C. has raised ( ) 5. We can help the old people ______ doing housework for them every weekend. A. by B. with C. for ( ) 6. —Has she cheered up the sick children in hospital? —No, she ______. She is busy preparing for the exam. A. hasn’t B. doesn’t C. didn’t ( ) 7. You ______ make an effort to help others; small actions can make a big difference. A. must B. should C. may ( ) 8. We joined a volunteer activity ______ helps the old people in our community. A. who B. that C. whom ( ) 9. You ______ not be rude to the people you help; kindness is the most important thing. A. should B. must C. may ( ) 10. They organized a charity sale ______ the homeless people can have a warm home. A. by B. with C. for 三、句型转换 1. I have volunteered in the community.（否定句） I __________ __________ volunteered in the community. 2. This is a volunteer activity that helps homeless people.（一般疑问句） __________ this a volunteer activity that __________ homeless people? 3. We should donate old books to poor children.（用could改写） We __________ __________ old books to poor children. 4. They have organized a charity sale for the sick children.（对划线部分提问） __________ __________ they organized for the sick children? 5. We help the old by doing housework for them.（对划线部分提问） __________ __________ we help the old? 6. She has donated three boxes of books to the poor.（改为一般疑问句并作否定回答） —__________ she __________ three boxes of books to the poor? —No, she __________. 7. This is a kind girl. She often helps sick children.（合并为定语从句） This is a kind girl __________ __________ helps sick children. 8. You should refuse to help others.（改为否定句） You __________ __________ to help others. 四、用should/could, 动词过去分词/定语从句引导词that/which/who, 介词填空 1. I __________ (volunteer) in the community to help old people since last term. 2. This is a charity sale __________ __________ (organize) by our school last week. 3. You __________ not give up helping others; it’s meaningful to make a difference. 4. We help homeless people __________ donating food and clothes to them. 5.—Have you ever met a volunteer __________ is always ready to help others? —Yes, I have. 6. She __________ (not cheer) up the sick children yet; she needs more time. 7. The volunteer work __________ we did last month was praised by our teacher. 8. We should help the poor __________ kindness and patience. 9. You __________ (could) help organize a volunteer activity to cheer up the homeless. 10. They have found a kind person __________ often helps the poor children with their studies. 参考答案 一、用所给词的适当形式填空 1. have volunteered 2. raises 3. Have; donated 4. should 5. haven’t organized 6. encouraged 7. shouldn’t 8. have already finished 9. did 10. has realized 二、单项选择 1.A 2.B 3.B 4.C 5.A 6.A 7.B 8.B 9.A 10.C 三、句型转换 1. haven’t; ever 2. Is; helps 3. could; donate 4. What; have 5. How; do 6. Has; donated; hasn’t 7. who; often 8. shouldn’t; refuse 四、用should/could, 动词过去分词/定语从句引导词that/which/who, 介词填空 1. have volunteered 2. that/which; was organized 3. should 4. by 5. who/that 6. hasn’t cheered 7. that/which 8. with 9. could 10. who/that 学科网（北京）股份有限公司 $