Section Ⅲ Grammar——时间状语从
句和省略
语 境 自 主 领 悟 先观察原句 ①Some of the DJs began speaking and shouting while the music played. ②“The moment I heard it，”he said，“I knew it was a completely new kind of music.” 1.句①～⑤中黑体部分在句中引导的是③The first time that rap artists recorded 时间状语从句，句⑥～⑦为省略句。 their music，musicians recorded the 2.句④⑤为no 后自主感悟 backing tracks (the music without the sooner...than.../hardly...when...句式，表示singing) in the studio and the rappers “一……就……”，且no sooner/hardlyadded their vocals later. 位于句首时，主句要用倒装语序。 ④No sooner had he reached home 3.句⑥是不定式的省略，省略了to后面than it began to rain. ⑤Hardly had I entered the room when the phone rang. ⑥—Do you want to go to the movie tonight？ —I hope to (go to the movie). ⑦While (I was) at college，I began to know him，a strange but able student. 的动词(短语)。 4.句⑦中，从句主语与主句主语一致，且从句中包含be动词的某种形式，可以将从句的主语和be动词同时省略。
一、时间状语从句
在复合句中起时间状语作用的句子称为时间状语从句。时间状语从句常用when，while，as，until，since或表示时间意义的名词短语等引导。
1．when，while，as的用法
连词 when 用法 从句谓语用延续性动词和非延续性动词均可，主、从句谓语表示的动作可同时或先后发生 从句谓语用延续性动词 while 表示两个延续性动作同时发生且具有对比意味，或一个动作发生在另一个动作进行的过程中 强调主、从句动作同时发生 as 表示“一边……一边……”之意 He was nine when his father died. 他父亲去世时他才九岁。
Jack was working in the lab when the power cut occurred.杰克正在实验室里工作，这时突然停电了。
They arrived while we were having dinner. 他们到时我们正在吃晚饭。
While I played the piano，my sister did her homework.我弹钢琴的时候姐姐在做作业。
As years go by，China is getting stronger and richer.随着时间一年一年过去，中国变得越来越富强了。
I saw my mother as I was getting off the bus. 我下公共汽车的时候看见了我妈妈。 [名师点津]
when在be about to do...when...，be doing...when...，had done...when...，be on one's way...when...，be on the point of doing...when...等结构中，作“正在那时”讲，表示某个动作正在发生或刚刚发生，另一动作同时发生。
He was about to leave when someone knocked at the door. 他刚要离开就有人敲门。
[即时演练1] 选词填空：when，while，as
①It's much easier to make friends when you have similar interests. ②While/When in Vienna he studied music. ③You will grow wiser as you grow older.
2．until，till的用法 主句形式 肯定句 主句谓语 用延续性动词 意义 意为“直到……为止”，表示主句中的动作到从句动作发生时结束 意为“直到……才……”，表示主句中的动作到从句动作发生时开始 否定句 用短暂性动词 He waited until she had finished speaking. 他一直等到她讲完。
You can't go home until you finish your work. 工作完成后你才能回家。 [名师点津]
(1)置于句首或在强调句中时常用until，其他情况until和till可通用。 Until you told me，I had no idea of it. 直到你告诉我，我对此事才有所了解。
(2)如果将“not until...”结构放在句首，那么主句要部分倒装。
Not until his bike looked almost new did he stop cleaning it.直到他的自行车看起来几乎像新的一样，他才停止擦洗。
3．before，since的用法 (1)before
①意为“在……之前”，置于主句前后均可。 Before the sun sets，we must go home. 太阳落山前，我们必须回家。
②如果before引导的从句位于主句之后，有时不能译成“在……之前”，而要译成“过了多久才……，还未……就”等。
The struggle lasted four years before the North won in the end. 斗争持续了4年北方才最终获胜。
He almost knocked me down before he saw me. 他几乎撞到我时才看见我。
She left before I could have a word with her. 我还没来得及和她说句话，她就离开了。
2019-2020同步外研英语选修七新突破讲义：Module 4 Section Ⅲ Grammar——时间状语从句和省略
