Unit 8 Making a difference.Section A Grammar Focus (4a-4d)导学案2025-2026学年人教版英语八年级下册

Unit 8 Making a difference.Section A Grammar Focus (4a-4d)导学案

一、学习目标

1. 掌握现在完成时中 for 与 since 的用法区别，能在语境中正确区分使用。
2. 熟练运用现在完成时表示“持续动作/状态”，掌握 How long have you…? 句型。
3. 能在句子、语篇和口语中正确运用 for/since 结构，提升语法运用能力。

二、课前预习：语法知识梳理

1. 核心用法对比

介词	含义	搭配结构	例句
for	表示动作/状态持续的时间段（时长）	for + 时间段（如：3 years, a long time, a few months）	I have been a volunteer for a few months.
since	表示动作/状态开始的时间点/过去事件	since + 时间点/过去事件（如：last August, 2020, he started）	She has been a volunteer since last August.

2. 关键句型

问句：How long have you/has he…?（询问持续时间）

回答：I’ve/He has … for… / since…

易错点：since 引导的从句用一般过去时，主句用现在完成时。

三、课堂练习（分层设计）

基础巩固练（语法辨析+句子填空）

1. 选择 for 或 since 填空

1. I have lived in this city ______ 2010.
2. She has been a teacher ______ 10 years.
3. They have known each other ______ they were children.
4. He has studied English ______ three months.
5. The organization has helped people ______ it was founded in 2005.

2. 用括号内动词的正确形式填空（现在完成时/一般过去时）

1. He ______ (volunteer) at the animal shelter ______ two years.
2. I ______ (be) a member of the club ______ last year.
3. She ______ (teach) kids English ______ she left college.
4. They ______ (collect) donations ______ over five years.
5. We ______ (not see) each other ______ we graduated from school.

能力提升练（语篇填空）

3. 用括号内动词的正确形式和 for/since 完成短文

I love being a volunteer! I ______ (work) with a local environmental group ______ almost two years now. ______ I joined the group, I ______ (take part in) over 15 clean-up activities. I ______ (make) many new friends there, and I even ______ (learn) how to plant trees. Last month, we ______ (organize) a tree-planting day in the park. It ______ (be) a great success. The park ______ (look) much greener now. I ______ (be) proud of what we ______ (do) together ______ we started.

拓展应用练（口语交际+句型仿写）

4. 仿照例句写对话（用 How long have you…? 句型）

例句：

A: How long have you known your best friend?

B: I’ve known her for 5 years / since we were in Grade 7.

请仿写3组对话（可参考话题：live in your neighborhood, study English, play basketball）