Unit 8 Making a difference 语法讲解（英语新教材人教版八年级下册）

该初中英语讲义通过框架结构系统梳理了现在完成时的知识体系，将for/since用法、非延续动词转换、时态对比等核心内容按“基础用法-重难点突破-综合应用”逻辑组织，用对比表格归纳非延续动词与延续性转换规则，清晰呈现知识脉络与内在联系。 讲义亮点在于分层练习设计与方法指导，如单项选择夯实基础、句型转换强化转换能力、短文改错聚焦易错点，结合标志词速记口诀培养学习能力，通过错误示例分析提升思维品质，助力不同层次学生掌握，为教师精准教学提供有效支持。

Unit 8 Making a difference现在完成时(for/since,非延续动词转换,时态对比) 语法详解 一、for 和 since 的用法 1. for + 时间段 用法：for 后面接时间段，表示动作持续了“长达……”。 教材原句： I have lived here for ten years.（我住在这里十年了。） 例句： She has waited for two hours.（她已经等了两个小时。） 练习题： ( ) 1. He has studied French ______ five years. A. since B. for C. from 2. since + 时间点 用法：since 后面接过去的时间点，表示从那个时间开始持续到现在。 教材原句： I have known him since 2010.（我从2010年就认识他了。） 例句： They have worked here since last month.（他们从上个月就在这里工作。） 练习题： ( ) 2. We have been friends ______ we were in primary school. A. for B. since C. before 3. 对 for/since 状语提问 用法：对 for 或 since 引导的时间状语提问，用 How long。 教材原句： — How long have you had this bike? — For about two months. 例句： — How long has she lived here? — Since 2015. 练习题： ( ) 3. — ______ have you kept this book? — For two weeks. A. How often B. How long C. How soon 4. 句型 It is / has been + 时间段 + since... 用法：表示“自从……以来已经多久了”。 教材原句： It has been three years since he left home.（他离家已经三年了。） 例句：It is two months since I saw him.（我两个月没见他了。） 练习题： ( ) 4. It ______ ten years since his grandfather passed away. A. has been B. is C. both A and B 二、非延续性动词的转换（重难点） 1. buy → have 用法：buy 是瞬间动词，不能与 for/since 连用，须转换为延续性动词 have。 教材对比： I have had it for 2 weeks.（我买它两周了。） 例句： He has had the car since last year.（这车他从去年就有了。） 练习题： ( ) 5. I ______ this computer for three years. A. have bought B. have had C. bought 2. borrow → keep 用法：borrow 是瞬间动词，转换为延续性动词 keep。 教材原句： · How long can I keep the book?（我能借这本书多久？） 例句： She has kept the dictionary for a month.（她借这本字典一个月了。） 练习题： ( ) 6. He ______ the library book since last Tuesday. A. has borrowed B. has kept C. borrowed 3. die → be dead 用法：die 是瞬间动词，转换为状态 be dead。 例句： His dog has been dead for a year.（他的狗死了一年了。） 练习题： ( ) 7. The famous scientist ______ for ten years. A. has died B. has been dead C. died 4. join → be in / be a member of 用法：join 是瞬间动词，转换为 be in 或 be a member of。 教材原句： He has been in the club since 2019.（他从2019年就在这个俱乐部了。） 例句： She has been a member of the team for two years. 练习题： ( ) 8. My uncle ______ the army for five years. A. has joined B. has been in C. joined 5. leave → be away (from) 用法：leave 是瞬间动词，转换为 be away。 教材原句： She has been away for an hour.（她离开一小时了。） 例句： They have been away from home since last Monday. 练习题： ( ) 9. He ______ from his hometown since 2018. A. has left B. has been away C. left 6. begin / start → be on 用法：begin/start 是瞬间动词，转换为 be on。 例句： The film has been on for 10 minutes.（电影已经开始了十分钟。） 练习题： ( ) 10. The meeting ______ for half an hour. A. has begun B. has been on C. began 7. arrive / come / go → be in / be at 用法：到达、来、去等瞬间动词转换为 be in/at。 教材原句： He has been in Beijing for 3 days.（他在北京待了三天了。） 例句：She has been at the station since 8 am. 练习题： ( ) 11. They ______ in New York since last Friday. A. have arrived B. have been C. arrived 三、现在完成时 vs 一般过去时 1. 一般过去时：强调过去事实，与现在无关 用法：动作发生在过去，只陈述过去发生过这件事。标志词：yesterday, last week, in 1990, just now, when I was young等。 教材原句： I lost my key yesterday.（我昨天丢了钥匙。——现在找到没有？不知道。） 例句： She went to the cinema last night.（她昨晚去电影院了。） 练习题： ( ) 12. I ______ my glasses just now. Have you seen them? A. have lost B. lost C. lose 2. 现在完成时：强调对现在的影响或持续到现在 用法：动作发生在过去，但对现在有影响或结果。标志词：already, yet, ever, never, just, before, so far, since, for等。 教材原句： I have lost my key.（我丢钥匙了。——现在钥匙还没找到，进不去门。） 例句：She has already finished her homework.（她已经完成了作业。——现在可以休息了。） 练习题： ( ) 13. —Where is your report? —I ______ it to the teacher already. A.gave B. have given C. give 3. 时态标志词速记 一般过去时标志：yesterday, ago, last..., just now, in 1990, when I was young... 现在完成时标志：already, yet, ever, never, just (刚刚), so far, since, for, in the past few years... 练习题： ( ) 14. She ______ to Japan in 2019. A. has been B. went C. goes ( ) 15. So far, we ______ 20% of the project. A. Completed B. have completed C. complete 四、易错点总结 for 和 since 的区别 for + 时间段 (for two years) since + 时间点 (since 2019 / since I came) 瞬间动词不能与for/since连用 错误：He has died for 3 years. 正确：He has been dead for 3 years. 一般过去时 vs 现在完成时 过去时：只讲过去事实，无关现在 完成时：强调对现在的影响或持续 标志词速记口诀 看到 ago/last/just now → 过去时 看到 for/since/so far → 完成时 【综合练习】 一、单项选择 ( ) 1. It ______ five years since we last met. A. Is B. was C. has ( ) 2. How long ______ you ______ the magazine? A. have; borrowed B. have; kept C. did; borrow ( ) 3. My grandmother ______ for two years. I miss her so much. A. has died B. has been dead C. died ( ) 4. I ______ to the new park last Sunday. It was beautiful. A. have been B. went C. go ( ) 5. They have been good friends ______ they were in kindergarten. A. For B. since C. Before 二、用 for 或 since 填空 1. I have waited here ______ three o'clock. 2. He has been a doctor ______ more than twenty years. 3. She has lived in this city ______ she got married. 4. We haven't seen each other ______ a long time. 5. It has been rainy ______ last Friday. 三、句型转换 1. He borrowed the book two weeks ago. (用现在完成时改写，保持原意) He ______ ______ the book for two weeks. 2. The film started ten minutes ago. (用现在完成时改写) The film ______ ______ ______ for ten minutes. 3. She left her hometown in 2015. (用现在完成时改写) She ______ ______ ______ from her hometown since 2015. 4. He joined the club three years ago. (用现在完成时改写) He ______ ______ ______ the club for three years. 5. I bought this phone last month. (用现在完成时改写) I ______ ______ this phone for one month. 四、完成句子 1. 我认识她已经十年了。 I ______ ______ her for ten years. 2. 自从他去了北京，我就没见过他。 I haven't seen him ______ he ______ to Beijing. 3. 你借这本书多久了？ How long ______ you ______ this book? 4. 他参军三年了。 He ______ ______ in the army for three years. 5. 会议已经开始半小时了。 The meeting ______ ______ ______ for half an hour. 五、短文改错 下列句子中各有一处错误，请找出并改正。 1. I have bought this bike for five years._____________________ 2. She has left her office since two hours ago._____________________ 3. It has been three years since we have graduated._____________________ 4. He has joined the chess club since last month._____________________ 5. My grandfather has died for ten years._____________________ ( 1 ) 学科网（北京）股份有限公司 $ Unit 8 Making a difference现在完成时(for/since,非延续动词转换,时态对比) 语法详解 一、for 和 since 的用法 1. for + 时间段 用法：for 后面接时间段，表示动作持续了“长达……”。 教材原句： I have lived here for ten years.（我住在这里十年了。） 例句： She has waited for two hours.（她已经等了两个小时。） 练习题： ( ) 1. He has studied French ______ five years. A. since B. for C. from 【答案】B。考查for的用法。five years是时间段，用for。 2. since + 时间点 用法：since 后面接过去的时间点，表示从那个时间开始持续到现在。 教材原句： I have known him since 2010.（我从2010年就认识他了。） 例句： They have worked here since last month.（他们从上个月就在这里工作。） 练习题： ( ) 2. We have been friends ______ we were in primary school. A. for B. since C. before 【答案】B。考查since的用法。“we were in primary school”是过去的时间点（从句），用since。 3. 对 for/since 状语提问 用法：对 for 或 since 引导的时间状语提问，用 How long。 教材原句： — How long have you had this bike? — For about two months. 例句： — How long has she lived here? — Since 2015. 练习题： ( ) 3. — ______ have you kept this book? — For two weeks. A. How often B. How long C. How soon 【答案】B。考查How long的用法。回答是时间段，用How long提问。 4. 句型 It is / has been + 时间段 + since... 用法：表示“自从……以来已经多久了”。 教材原句： It has been three years since he left home.（他离家已经三年了。） 例句：It is two months since I saw him.（我两个月没见他了。） 练习题： ( ) 4. It ______ ten years since his grandfather passed away. A. has been B. is C. both A and B 【答案】C。考查“It is/has been + 时间段 + since”句型。两种表达均可，has been更正式。 二、非延续性动词的转换（重难点） 1. buy → have 用法：buy 是瞬间动词，不能与 for/since 连用，须转换为延续性动词 have。 教材对比： I have had it for 2 weeks.（我买它两周了。） 例句： He has had the car since last year.（这车他从去年就有了。） 练习题： ( ) 5. I ______ this computer for three years. A. have bought B. have had C. bought 【答案】B。考查buy转换为have。for three years表示时间段，用have had。 2. borrow → keep 用法：borrow 是瞬间动词，转换为延续性动词 keep。 教材原句： · How long can I keep the book?（我能借这本书多久？） 例句： She has kept the dictionary for a month.（她借这本字典一个月了。） 练习题： ( ) 6. He ______ the library book since last Tuesday. A. has borrowed B. has kept C. borrowed 【答案】B。考查borrow转换为keep。since last Tuesday表示从上周二到现在，用has kept。 3. die → be dead 用法：die 是瞬间动词，转换为状态 be dead。 例句： His dog has been dead for a year.（他的狗死了一年了。） 练习题： ( ) 7. The famous scientist ______ for ten years. A. has died B. has been dead C. died 【答案】B。考查die转换为be dead。for ten years表示时间段，用has been dead。 4. join → be in / be a member of 用法：join 是瞬间动词，转换为 be in 或 be a member of。 教材原句： He has been in the club since 2019.（他从2019年就在这个俱乐部了。） 例句： She has been a member of the team for two years. 练习题： ( ) 8. My uncle ______ the army for five years. A. has joined B. has been in C. joined 【答案】B。考查join转换为be in。for five years表示时间段，用has been in。 5. leave → be away (from) 用法：leave 是瞬间动词，转换为 be away。 教材原句： She has been away for an hour.（她离开一小时了。） 例句： They have been away from home since last Monday. 练习题： ( ) 9. He ______ from his hometown since 2018. A. has left B. has been away C. left 【答案】B。考查leave转换为be away。since 2018表示从2018年到现在，用has been away。 6. begin / start → be on 用法：begin/start 是瞬间动词，转换为 be on。 例句： The film has been on for 10 minutes.（电影已经开始了十分钟。） 练习题： ( ) 10. The meeting ______ for half an hour. A. has begun B. has been on C. began 【答案】B。考查begin转换为be on。for half an hour表示时间段，用has been on。 7. arrive / come / go → be in / be at 用法：到达、来、去等瞬间动词转换为 be in/at。 教材原句： He has been in Beijing for 3 days.（他在北京待了三天了。） 例句：She has been at the station since 8 am. 练习题： ( ) 11. They ______ in New York since last Friday. A. have arrived B. have been C. arrived 【答案】B。考查arrive转换为be in。since last Friday表示从上周五到现在，用have been。 三、现在完成时 vs 一般过去时 1. 一般过去时：强调过去事实，与现在无关 用法：动作发生在过去，只陈述过去发生过这件事。标志词：yesterday, last week, in 1990, just now, when I was young等。 教材原句： I lost my key yesterday.（我昨天丢了钥匙。——现在找到没有？不知道。） 例句： She went to the cinema last night.（她昨晚去电影院了。） 练习题： ( ) 12. I ______ my glasses just now. Have you seen them? A. have lost B. lost C. lose 【答案】B。考查一般过去时。just now（刚才）是过去时间标志，用lost。 2. 现在完成时：强调对现在的影响或持续到现在 用法：动作发生在过去，但对现在有影响或结果。标志词：already, yet, ever, never, just, before, so far, since, for等。 教材原句： I have lost my key.（我丢钥匙了。——现在钥匙还没找到，进不去门。） 例句：She has already finished her homework.（她已经完成了作业。——现在可以休息了。） 练习题： ( ) 13. —Where is your report? —I ______ it to the teacher already. A.gave B. have given C. give 【答案】B。考查现在完成时。already表示“已经”，强调对现在的影响（报告已交），用have given。 3. 时态标志词速记 一般过去时标志：yesterday, ago, last..., just now, in 1990, when I was young... 现在完成时标志：already, yet, ever, never, just (刚刚), so far, since, for, in the past few years... 练习题： ( ) 14. She ______ to Japan in 2019. A. has been B. went C. goes 【答案】B。考查一般过去时。in 2019是明确的过去时间，用went。 ( ) 15. So far, we ______ 20% of the project. A. Completed B. have completed C. complete 【答案】B。考查现在完成时。so far（到目前为止）是现在完成时标志，用have completed。 四、易错点总结 for 和 since 的区别 for + 时间段 (for two years) since + 时间点 (since 2019 / since I came) 瞬间动词不能与for/since连用 错误：He has died for 3 years. 正确：He has been dead for 3 years. 一般过去时 vs 现在完成时 过去时：只讲过去事实，无关现在 完成时：强调对现在的影响或持续 标志词速记口诀 看到 ago/last/just now → 过去时 看到 for/since/so far → 完成时 【综合练习】 一、单项选择 ( ) 1. It ______ five years since we last met. A. Is B. was C. has ( ) 2. How long ______ you ______ the magazine? A. have; borrowed B. have; kept C. did; borrow ( ) 3. My grandmother ______ for two years. I miss her so much. A. has died B. has been dead C. died ( ) 4. I ______ to the new park last Sunday. It was beautiful. A. have been B. went C. go ( ) 5. They have been good friends ______ they were in kindergarten. A. For B. since C. Before 【答案】1. A；2. B；3. B；4. B；5. B 1. A。考查“It is/has been + 时间段 + since”句型。两种均可，is更常用。 2. B。考查borrow转换为keep。表示“借了多久”用have kept。 3. B。考查die转换为be dead。for two years不能用has died。 4. B。考查一般过去时。last Sunday是过去时间，用went。 5. B。考查since。were in kindergarten是过去时间点，用since。 二、用 for 或 since 填空 1. I have waited here ______ three o'clock. 2. He has been a doctor ______ more than twenty years. 3. She has lived in this city ______ she got married. 4. We haven't seen each other ______ a long time. 5. It has been rainy ______ last Friday. 【答案】1. since。three o'clock是时间点。 2. for。more than twenty years是时间段。 3. since。she got married是过去时间点（从句）。 4. for。a long time是时间段。 5. since。last Friday是过去时间点。 三、句型转换 1. He borrowed the book two weeks ago. (用现在完成时改写，保持原意) He ______ ______ the book for two weeks. 2. The film started ten minutes ago. (用现在完成时改写) The film ______ ______ ______ for ten minutes. 3. She left her hometown in 2015. (用现在完成时改写) She ______ ______ ______ from her hometown since 2015. 4. He joined the club three years ago. (用现在完成时改写) He ______ ______ ______ the club for three years. 5. I bought this phone last month. (用现在完成时改写) I ______ ______ this phone for one month. 【答案】1. has kept。borrow → keep。 2. has been on。begin → be on。 3. has been away。leave → be away。 4. has been in。join → be in。 5. have had。buy → have。 四、完成句子 1. 我认识她已经十年了。 I ______ ______ her for ten years. 2. 自从他去了北京，我就没见过他。 I haven't seen him ______ he ______ to Beijing. 3. 你借这本书多久了？ How long ______ you ______ this book? 4. 他参军三年了。 He ______ ______ in the army for three years. 5. 会议已经开始半小时了。 The meeting ______ ______ ______ for half an hour. 【答案】1. have known。认识是延续性动词。 2. since; went。since + 一般过去时从句。 3. have; kept。借书多久用how long + have kept。 4. has been。join → be in。 5. has been on。begin → be on。 五、短文改错 下列句子中各有一处错误，请找出并改正。 1. I have bought this bike for five years._____________________ 2. She has left her office since two hours ago._____________________ 3. It has been three years since we have graduated._____________________ 4. He has joined the chess club since last month._____________________ 5. My grandfather has died for ten years._____________________ 【答案】1. have bought → have had。buy是瞬间动词，不能与for连用。 2. has left → has been away from。leave是瞬间动词，不能与since连用。 3. have graduated → graduated。It has been...since后跟一般过去时。 4. has joined → has been in。join是瞬间动词。 5. has died → has been dead。die是瞬间动词，不能与for连用。 ( 1 ) 学科网（北京）股份有限公司 $