第04讲 预习九上：时间、条件和原因状语从句-【暑假自学课】2023年新九年级英语暑假精品课（外研版）

第04讲 预习下册：时间、条件和原因状语从句 掌握并正确使用时间、条件和原因状语从句。 在复合句中，做状语成分的从句叫状语从句。 常见的状语从句可分为：时间、条件、地点、原因、方式、让步、比较、结果、目的等从句，由不同的引导词引导。 考点一：时间状语从句 引导词 用法 例句 when when引导的时间状语从句中既可接延续性动词，也可接非延续性动词，多用一般过去时 They were talking happily when I walked past the door.当我从门前走过，他们正在开心地聊天。 while while强调主句和从句动作同时发生，所引导的时间状语从句只能用延续性动词，多用进行时态。 My mother was cooking while I was doing my homework. 当妈妈在做饭的时候，我在做作业。 not … until 主句的谓语动词为非延续性动词，主句要用否定式，从句用肯定式。 The bus won’t start until everybody gets on. 公共汽车直到每个人都上车才会发动。 since 主句谓语动词一般用现在完成时，从句谓语动词一般用一般过去时。 Five yeas has passed since we saw each other last time. 距离我们上次见面已经五年过去了。 before before 引导的从句表示主句的动作发生在从句动作之前。 We turned off the light before we left. 我们在离开前关了灯。 after after 引导的从句表示主句的动作发生在从句动作之后。 He went to bed after he finished his work. 他做完工作后就去睡觉了。 as soon as 若主句为一般将来时，从句常用一般现在时表将来。 I will tell him the news as soon as I see him. 我一看见他，就会告诉他这个消息。 考点二：条件状语从句 条件状语从句的引导词主要有if和unless，两者可转换。 在条件状语从句中，从句常用一般现在时表将来，即主将从现。 如：You will fail the exam if you don’t work hard.=You will fail the exam unless you work hard. 如果不努力学习，你考试会不及格的。 考点三：原因状语从句 原因状语从句的引导词有because，since，as等。 注意：1. because和so不能同时使用。 如：He didn’t come to school yesterday because he was ill. 他昨天没来上学，因为他生病了。 2. since引导原因状语从句表示显然的或已为人知的理由，表示“因为，既然” 如：since everyone is here, let’s start.既然大家都到期了，我们就开始吧。 考点一：时间状语从句 1．（2022秋·辽宁沈阳·九年级沈阳市杏坛中学校考期末）I waited for Tim ________ he was doing his homework. A．so that B．unless C．while D．although 2．（2023·辽宁沈阳·统考三模）The boy was so quiet that often no one would notice ________ he came in the room. A．because B．unless C．while D．when 3．（2023·福建南平·统考二模）ChatGPT has influenced people’s life a lot since it ________. A．is developed B．was developed C．will be developed 4．（2023·江西上饶·校联考一模）You may never really understand a person ________ you consider things from his point. A．until B．while C．because D．but 5．（2023·福建漳州·统考二模）It is said that Zhang Sanfeng created tai chi(太极) ________ he had watched a fight between snake and a bird. A．until B．after C．when