状语从句精讲 课件.pptVIP

状语从句的位置比较灵活，有时可以放于句首，有时可以置于句末。状语从句位于句首时，其后常用逗号与后面的句子隔开。 状语从句可以根据其用途分为： 时间状语从句、地点状语从句、原因状语从句、结果状语从句、目的状语从句、条件状语从句、让步状语从句、比较状语从句、方式状语从句。 连接词while的用法小结 1. while引导的动作必须是持续性的，在……期间，往往指一段时间。如： While we were talking, he came in. Please don’t talk so loud while others are working. 2. while作为并列连词，意为“而，却”，侧重主句动作和从句动作相对比。We are cleaning the classroom while they are playing the football. 3. while可表示尽管，相当于although。 连接词when, while, as的用法区别： 1．while引导的时间状语从句的谓语动词必须是可延续的， 而when引导的时间状语从句的谓语动词是可延续的，也 可以是表短暂性动作的动词。如：When/While he was eating his breakfast, he heard the doorbell ring. When I stopped my car, a man came up to me. (不可延续，短暂性动词，只可以用when，不可用while) 2．表示“随着……”，连词用as，不用when或while。如： As the day went on, the weather got worse. 3．如果主句表示的是短暂动作，而从句用延续性动作的进行时态表示在一段时间内正在进行的动作时，when, while 与as 可互换使用。如： When/While/As I was walking down the street, I came across an old friend of mine. 4.从句动作发生在主句动作之前时，只能用when引导这个从句，不可用as或while。 如 When you have finished your work, you may have a rest. When the children had gone to bed, she began to prepare her lessons.（这个时候的 when= after） since 在it is/ has been +段时间+since从句中，时间的计算从since从句的动作完成或状态结束时算起。如： It is three years since she was in our class. It is three years since he lived here 她离开我们班有三年了。 他不住这儿有三年了。 比较 it is three years since I smoked a cigar. It is three years since I began to smoke. 我不吸烟有三年了。 我吸烟有三年了 考点:as soon as “一 … 就” “刚….就” 我一到达上海就给你打电话。（时态） 时态要求 1. It wasn’t until nearly a month later ___ I received the manager’s reply. A. since B. when C. as D. that 考点: 易混淆句型 it is + 时间+ since before when that It is five years ______he finished his research. It was five years ______he finished his research. It was five years later _______he finished his research. ? It was 5 o’clock _____ he got home. It was at 5 o’clock _____ he got home. 在地点状语从句之前，不要使用介词。 【误】You should put the book at where it was. 【正】You should put the book where