时间状语从句（一次讲清楚时间状语从句）,1.when, while,as引导的时间状语从句的主、从句动作发生的顺序及主、从句的时态要求。,(1)主、从句动作发生的顺序,when与as引导的时间状语从句，主、从句谓语动词可以同时发生也可以先后发生; while引导的时间状语从句，主、从句谓语动词同时发生或主句动作发生在从句动作进行的过程中。,When he had finished his homework. he took a short rest,当他完成作业后，他稍微休息了一会儿。(从句动作先发生),I got to the airport, the guests had left.,当我赶到机场时，客人们已经离开了。(从句动作后发生),While we were working in the field, it suddenly began to rain,当我们正在地里劳动时，天忽然下起雨来。,(2)主、从句的时态要求,如果主句的动作发生于从句的动作进行的过程中，从句常用进行时。,Someone broke into the house when/while/as she was sleeping,在她睡觉时有人闯人屋里。,2.表示时间先后的连词主要包括 before和 after.,after,表示“在……之后”。,before可表达多种意义:“…之后オ…”":“还没来得及……就……”等。,before常用于以下句型,It will be+时间段+ before..(从句用一般现在时)要过多长时间才,It won't be+时间段+ before.(从句用一般现在时)过不了多长时间就,t wasn' t long before.(从句用一般过去时)没过多久就,It was+时间段+ before..(从句用一般过去时)过了多长时间才,It will be half a year before I come back.半年之后我才回来。,It won't be long before we meet again.过不了多久我们就会再见面。,wasn't long before he left the cour过多久他就离开了这个国家。,After the students came to the lab, the professor brought out three bottles,们到实验室后，教授拿出了3个瓶子。,3.表示“延续性”和“非延续性”的连词主要包括 since、 till/until等。,(1)在含有 since引导的时间状语从句的复合句中，从句中谓语动词多用一,般过去时，而主句中谓语动词多用现在完成时。,I have lived here since I came here,自从我来到这儿，我就住在这儿。,(2)il和umti(tiI不可以位于句首):在肯定句中，主句的谓语动词是延续,性动词，而在否定句中，主句的谓语动词是非延续性动词。,He waited until/till his mother came b百思特网ack,他一直等到他妈妈回.,I didn't go to bed until,ill I fin,到做完作业我才上床睡觉,7,4.表示“一(刚)…就的连词(短语),nediately,directly, no sooner.han、 hardly/scarcely.hen等。,I told him the news the moment I saw him,to,我一看见他就把那则消息告诉他了。,No sooner 百思特网had he got to the station than the bus left,他刚到车站，公交车就离开了。,温馨提示:在 no sooner. than和 hardly/scarce.hen.结构中，当no...sooner和 hardly/ scarcely位于句百思特网首时，主句要用部分倒装。,gave,-Hardly had I got home when it began to rain,我刚到家，天就开始下雨了。,5.表示“经常性或习惯性”的连词: each time、 every time、 whenever等。,He is busy working each time I see hi,我每次看见他，他都在忙着工作。,Whenever I see her, she always wears a smile,无论我什么时候看到她，她总是面带微笑。,