Unit1语法讲解及习题：时间状语从句（一）Adverbial clauses of time (I)2026-2027学年沪教版英语八年级上册

该初中英语知识清单系统梳理了沪教牛津八上Unit1时间状语从句（一）内容，涵盖before、when、as、until四大引导词的定义、用法、时态规则及从句位置，搭配专项练习题，搭建从基础概念理解到语法应用实践的递进式学习支架。 清单按引导词分类呈现知识体系，突出“主将从现”时态规则和从句位置差异，通过单项选择、句型改写等题型强化应用，参考答案附详细解析培养学生语言能力和思维品质。特别设计“not…until否定结构”“as动作同步强调”等应用提示，不同基础学生可高效掌握，教师可据此设计针对性教学活动，提升课堂实效。

沪教牛津英语八上Unit1语法讲解及习题： 时间状语从句（一）Adverbial clauses of time (I) 一、核心语法知识点详解 1. 定义 时间状语从句：由时间连词引导，用来表示主句动作发生时间的从句。本单元学习 4 个核心引导词：before, when, as, until，从句可放在主句前或主句后。 2. 四大引导词用法 （1）before 在…… 之前 含义：从句动作发生在主句动作之前 时态规则：主将从现（主句将来时，从句一般现在时） 结构：主句 + before + 从句 / Before + 从句，主句 例句：We will save water before the river dries up. 我们要在河流干涸之前节约用水。 （2）when 当…… 时候 含义：主句和从句动作可以同时发生，也可以先后发生，适用范围最广 例句：When people waste lots of water, the underground water will decrease. 当人们大量浪费水时，地下水会减少。 （3）as 一边…… 一边；随着 含义：强调两个动作同步进行，伴随发生 例句：As we wash hands, we should turn off the tap in time. 我们洗手的时候，要及时关掉水龙头。 （4）until 直到…… 为止 两种结构 ① 肯定句：主句延续性动词 + until，动作持续到从句时间结束 ② 否定句：not … until 直到…… 才，从句动作发生后主句动作才启动 例句：We reuse the rainwater until it is used up. 我们循环利用雨水，直到用完为止。 3. 核心时态规则：主将从现 主句：一般将来时（will do /be going to do） 时间状语从句：一般现在时表将来，绝不使用 will 例：When the drought comes, many plants will die.（✅） When the drought will come, many plants die.（❌） 4. 从句位置 从句在前：从句 + 逗号 + 主句 Before you leave, please turn off the tap. 从句在后：主句直接 + 从句，无逗号 Please turn off the tap before you leave. 二、专项练习题 题型一：单项选择 1. We should protect water __________ it is too late. A. when B. before C. until D. as 2. __________ people pollute rivers, the sea will also get dirty. A. Before B. Until C. When D. As 3. I will wait __________ you finish checking the water-saving equipment. A. until B. before C. when D. as 4. __________ we use recycled water, we save more fresh water every day. A. As B. Until C. Before D. When 5. He will fix the broken tap __________ the water leaks everywhere. A. until B. before C. when D. as 6. You can’t drink the water __________ you boil it first. A. when B. as C. until D. before 7. __________ the temperature rises, more water will evaporate（蒸发）. A. As B. Until C. Before D. When 8. We will start the water-saving activity __________ the bell rings. A. until B. before C. when D. as 9. Don’t leave the bathroom __________ you turn off all the taps. A. when B. until C. as D. before 10. I will write a water protection proposal __________ I finish my survey. A. before B. when C. until D. as 题型二：用 before/when/as/until 填空 1. __________ you take a shower, remember to collect the used water. 2. The groundwater will run out __________ we take no action now. 3. She keeps reusing water __________ there is nothing left. 4. __________ the rain falls, the dry land becomes green again. 5. I will check the pipe __________ it breaks and causes a flood. 6. You can’t use the drinking water __________ workers clean it. 7. __________ we wash vegetables, we can keep the water for watering flowers. 8. Many animals will die __________ the lake dries up completely. 9. He watches water science videos __________ he has free time. 10. We will stay in the lab __________ we finish the water experiment. 题型三：连词成句 1. people / waste water / the environment / get worse (when) 2. we / save every drop of water / the drought / come (before) 3. the students / do experiments / they / learn water knowledge (as) 4. I / wait / my father / repair the leaking tap (until) 5. you / finish the report / hand it in (when) 6. we / take actions / it / become too late (before) 题型四：句型改写（合并为时间状语从句） 1. People cut down trees. Less rain will fall. (when) 2. The river gets dirty. Fish will disappear. (before) 3. The sun shines strongly. Water turns into steam. (as) 4. The rain stops. We will go to check the reservoir. (until) 题型五：句子翻译 1. 在干旱来临之前，我们应该修建更多水库。(before) 2. 随着城市发展，人们的用水量越来越大。(as) 3. 直到水资源短缺，人们才会意识到节水的重要性。(not…until) 三、参考答案 + 详细解析 题型一：单项选择 1. B 解析：before 在为时已晚之前，符合 “提前保护水资源” 语境 2. C 解析：when 当…… 时，引导条件性时间状语从句 3. A 解析：until 等待直到你检修完设备，延续性动词搭配 until 4. A 解析：as 伴随，一边循环用水一边节约淡水 5. B 解析：before 在漏水泛滥之前修好水龙头 6. C 解析：not…until 固定搭配，直到烧开才能饮用 7. A 解析：as 随着气温升高，水蒸发，同步变化 8. C 解析：when 铃响的时候启动活动 9. B 解析：not…until 直到关掉水龙头再离开 10. B 解析：when 完成调查后写倡议书 答案：1.B 2.C 3.A 4.A 5.B 6.C 7.A 8.C 9.B 10.B 题型二：选词填空 1. Before 2. before 3. until 4. As 5. before 2. until 7. As 8. when 9. when 10. until 解析： before：强调提前预防；as：动作同步伴随；until：动作持续到终点；when：时间点触发动作 题型三：连词成句 1. When people waste water, the environment will get worse. 2. We should save every drop of water before the drought comes. 3. As the students do experiments, they learn water knowledge. 4. I will wait until my father repairs the leaking tap. 5. Hand it in when you finish the report. 6. We must take actions before it becomes too late. 题型四：句型改写 1. When people cut down trees, less rain will fall. 2. Fish will disappear before the river gets dirty. 3. As the sun shines strongly, water turns into steam. 4. We won’t go to check the reservoir until the rain stops. 题型五：句子翻译 1. We should build more reservoirs before the drought comes. 2. As cities develop, people use more and more water. 3. People won’t realize the importance of saving water until water is in short supply. ( 1 ) 学科网（北京）股份有限公司 $