Unit 8 when /while/as 知识点汇总2026-2027学年译林版英语八年级上册

Unit 8 when /while/as 知识点汇总 一、基本含义 when、while、as 都可翻译为“当……时候”，引导时间状语从句，常搭配过去进行时使用，三者核心区分依据：从句动词是瞬间动词还是延续性动词。 二、三者详细用法 （一）while 1. 从句谓语只能是延续性动词（read、cook、run、sleep、watch TV），从句多用进行时态； 2. 不能搭配瞬间动词（wake up、arrive、ring、come、leave、happen）； 3. 经典结构：过去进行时 + while + 过去进行时，表示两个长动作同步持续进行。 例句：While she was making a phone call, I was writing an email. 她打电话的时候，我正在写邮件。 错误示例：❌ While he woke up…（wake up 瞬间动作，不可用while） （二）when 1. 适用范围最广，从句既能接瞬间动词，也能接延续性动词；可指时间点，也可指时间段； 2. 必考固定结构：过去进行时 + when + 一般过去时，主句长动作进行时，突然发生短暂突发动作。 例句：I was walking in the street when he called me. 我正在街上走路，这时他突然打来电话。 When he woke up, it was eight o’clock. 他醒来时已经八点了。 （三）as 1. 侧重“一边……一边……”，强调动作伴随同步发生； 2. 延续动词、瞬间动词大多都能使用，多数场景可与when、while互换。 例句：I saw a traffic accident as I was riding to school. 我骑车上学途中看见了一起交通事故。 三、四大必考固定句式 1. 长动作作背景，突发短暂动作 结构：主语 was/were doing… when 主语 did… 例：We were having dinner when it rained heavily. 我们正在吃晚饭，突然下起大雨。 2. 两个持续性动作同步并行 结构：主语 was/were doing… while 主语 was/were doing… 例：They were rowing boats while we were climbing the hill. 我们爬山的时候，他们在划船。 3. 时间点发生瞬时动作 结构：When/As + 主语 did…（瞬间动词） 例：When/As he arrived, there were many people in the meeting room. 他抵达时，会议室里已经有很多人。 4. 一边做一件事，一边做另一件事 结构：as + 进行时态，表伴随 例：She sang songs as she was washing clothes. 她一边洗衣服一边唱歌。 四、快速判断口诀 1. 从句为瞬间动词（醒来、抵达、铃响）：只用 when / as，禁用 while； 2. 从句为持续进行长动作：when / while / as 三者通用； 3. 两件事长时间同步进行：优先选用 while； 4. 长动作中途插入突发小动作：固定使用 when。 五、动词分类 1. 瞬间动词（不可用while）：wake up, arrive, ring, come, leave, stop, happen 2. 延续动词（三者通用）：read, cook, study, run, sleep, watch TV 六、典型正误对比 1. ✔ When/As he woke up… 　❌ While he woke up… 2. ✔ While I was waiting for the bus, I met her. ✔ When/As I was waiting for the bus, I met her. 3. ✔ I was reading when a stranger came in.（突发闯入，用when） 4. ✔ While we were reading, a stranger came in.（读书作背景，三者均可） 配套练习题 一、单项选择题 1. ______ he woke up at eight o’clock, his mother was cooking breakfast. A. While B. When C. Since 2. I met my old classmate ______ I was waiting for the bus at the stop. A. When B. While C. A和B都可以 3. It began to rain suddenly ______ we were having dinner last night. A. when/while/as B. only while C. only when 4. We can’t use while here, because arrive is a ______ action. A. continuous B. momentary C. long-lasting 5. ______ I was riding to school, I saw a traffic accident on the road. A. While/As B. While only C. When only 6. They ______ basketball on the playground while we ______ English songs yesterday afternoon. A. played; sang B. were playing; were singing C. are playing; sing 7. ______ she was talking on the phone, her little brother broke a glass carelessly. A. when/while/as B. while only C. as only 8. He fell down ______ he was running on the playground just now. A. when B. while C. 三者均可 9. ______ the bell rang, we were reading books quietly in the classroom. A. While B. When C. As 10. I ______ TV when my father came back home yesterday evening. A. watch B. watched C. was watching 二、用所给动词适当形式填空 1. He ________ (sleep) deeply when someone ________ (knock) at the door last night. 2. While my parents ________ (talk) about daily things, I ________ (do) English exercises. 3. I ________ (walk) along the street when I ________ (meet) my primary school friend. 4. When the accident ________ (happen), they ________ (drive) to the countryside. 5. She ________ (not read) storybooks while her brother ________ (play) computer games yesterday evening. 三、句型转换 1. I was cleaning the window. My aunt arrived.（用合适连词合并为一句） ________________________________________________________________ 2. While she was watching TV, her father was reading newspapers.（改用as改写同义句） ________________________________________________________________ 3. He was playing basketball when it began to rain.（改为否定句） ________________________________________________________________ 4. They were swimming in the pool while we were running.（改为一般疑问句，并作否定简略回答） ________________________________________________________________ ________________________________________________________________ 5. When I called him, he was having a shower.（对划线部分was having a shower提问） ________________________________________________________________ 四、改错（划出错误并改正） 1. While he arrived at the station, his friend was waiting for him outside. ____________ 2. I was cook dinner when my sister came back home yesterday. ____________ 3. While the bell ring, we were having a math test in the classroom. ____________ 4. When he was fall asleep, his mother covered him with a quilt. ____________ 五、翻译句子 1. 我正在写作业的时候，突然停电了。 ________________________________________ 2. 妈妈做饭时，爸爸在看报纸。 ________________________________________ 3. 他过马路时看见了一场交通事故。 ________________________________________ 4. 我们爬山的时候，他们正在河边钓鱼。 ________________________________________ 参考答案与解析 一、单项选择题 1.B 解析：wake up是瞬间动词，只能用when 2.C 解析：wait是延续动词，when、while均可 3.A 解析：have dinner为延续动作，三者通用 4.B 解析：arrive是瞬间短暂动作 5.A 解析：ride延续动作，while、as通用 6.B 解析：while连接两个同步进行的过去长动作，均用过去进行时 7.A 解析：talk延续动词，三者都能使用 8.C 解析：run延续动词，when/while/as均可 9.B 解析：ring铃响是瞬间动词，只用when 10.C 解析：过去进行时搭配when引导的短暂动作 二、动词适当形式填空 1. was sleeping; knocked 2. were talking; was doing 3. was walking; met 4. happened; were driving 5. wasn’t reading; was playing 三、句型转换 1. I was cleaning the window when my aunt arrived. 2. As she was watching TV, her father was reading newspapers. 3. He wasn’t playing basketball when it began to rain. 4. Were they swimming in the pool while we were running? No, they weren’t. 5. What was he doing when you called him? 四、改错 1. While → When/As arrive是瞬间动词，不能用while 2. cook → cooking was后接动词-ing构成过去进行时 3. ring → rang 全文过去时态，ring用过去式 4. fall → falling was后接doing构成进行时 五、翻译句子 1. I was doing my homework when the power went out suddenly. 2. While my mother was cooking, my father was reading newspapers. 3. He saw a traffic accident when/as he crossed the road. 4. While we were climbing mountains, they were fishing by the river. 学科网（北京）股份有限公司 $