外研版英语必修二Module5时间原因状语从句讲解分析.ppt

时间状语从句 由连词when, while, as, as soon as, before, after, till/ until等引导。 主句用将来时，从句常用一般现在时表将来。（主将从现） * I will tell him when he comes back. 1. 连接词when, while, as的用法区别 when, while, as这三个连词都可表示“当……的时候”，使用时应注意： 1) when可表示一个时间点，也可表示一个时间段。 When he came in, we were having supper. When we were having supper, the light suddenly went out. 2) while则只表示一个时间段。它所引导的时间状语从句中的时态常用进行时态。 When/While he was eating his breakfast, he heard the doorbell ring. 3) as 着重指从句的动作与主句的动作相伴随发生。“随着……”，“一边……一边……” 。 She sang as she walked along the street. As the election approached, the violence（暴行） got worse. 连接词when的用法小结 when引导时间状语从句，意为“当……的时候” 2. when 用作并列连词，常用于下列结构中，表示某件事正在发生,正要发生或刚刚发生，另一动作同时或紧接着发生。意为“就在那时/这时”,相当于and then , and at this/ that time。 was/were doing …when… was/were about to do…when… was/were on the point of doing …when… had done…when… I was on the point of reading books when someone knocked at the door. We were about to start when it began to rain. I was playing computer games when mom came in. I had just got home when it began to rain heavily/hard. 3. It is/was+时间点+when… 当…时已是…时候了 It was already 12 o’clock ______ I got home. It was already at 12 o’clock ______ I got home. 4. when表示“既然; 考虑到” How can I help them to understand when they won’t listen to me? 5. when 表示“虽然; 然而; 可是” She claimed to be 18, when I knew she was only 16. when that 1. (04北京春) We were swimming in the lake ______ suddenly the storm started. A. when B. while C. until D. before 2. (02上海) He was about to tell me the secret ______ someone patted him on the shoulder. A. as B. until C. while D. when 3. (05上海) He transplanted the little tree to the garden ______ it was the best time for it. A. where B. when C. that D. until 4. (05福建) －Did Jack come back early last night? －Yes. It was not yet eight o’clock ____ he arrived home. A. Before B. when C. that D. until 5. (06辽宁) He was