2015届高考英语一轮复习 语法讲解 从句 连词when,while,as的用法区别课件 新人教版.ppt

* 13 ___ the day went on, the weather got worse. A. With B. When C. While D. As ◆ ◆ 15 连词when, while, as的用法区别 _____ volleyball is her strength, she’s also great at basketball. Since B. Once C. Unless D. While 12 D。考查让步状语从句。 while表示“虽然，尽管” ，符合语境。尽管排球是 她的强项，但是她也擅长 打篮球。 解析/显隐 解析/显隐 D。句意:随着时间的推移， 天气变得越来越糟糕。as 表示发展、变化的情况。 难 点 自 测 难 点 诠 释 ◆ ◆ 15 连词when, while, as的用法区别 难 点 诠 释 (1)作并列连词,意思是“这时”(at this time),常 用于下列句型： ① was/were doing…when…某事正在进行,这时 发生了另外一件事。 We were walking when I heard a cry of help. ② was/were about to…when…即将做某事,这时 发生了另外一件事。 I was about to leave when it began to rain. ◆ ◆ 15 连词when, while, as的用法区别 难 点 诠 释 ③had just done…when…某事刚发生，就发生了另 外一件事；某事情还没有持续多长时间，就发生了 另外一件事。 We had just sat down when someone knocked at the door. We hadn’t been asleep for long when we heard a terrible noise. ◆ ◆ 15 连词when, while, as的用法区别 难 点 诠 释 (2) 表示“既然”。 Why do you want a new job when you’ve got such a good one already? (3)表示“虽然”，然而，可是”，一般位于句中。 He walks when he can take a taxi. ◆ ◆ 15 连词when, while, as的用法区别 难 点 诠 释 (1)表示对比或比较，意为“然而，而”。 He likes dancing while his brother likes singing. (2) 表示“虽然，尽管”，用于句首。 While she loves her students, she is very strict with them. ◆ ◆ 15 连词when, while, as的用法区别 难 点 诠 释 表示发展、变化的情况时，只能用as。 As he grew older, he lost interest in everything except gardening. when, while, as的用法共同点 在说明事情发生的背景时,使用when, while, as 都可以。如: He broke his leg when/while/as he playing football. 表示“当…的时候”, 可以使用when, 也可以使用 while。when从句中的谓语动词可以是延续性的,也可 以是非延续性的,而while从句中的动词必须是延续性 的。as引导时间状语从句时,表示“一边…一边…”。强 调主句和从句的动作同时进行。例如: It was nine o’clock when I got home.(非延续) He was reading while he was waiting for a bus.(延续） The girl sings as she goes to school. (同时发生) ◆ ◆ 15 连词when, while, as的用法区别 典例2 In some places women work outside to earn money ___ men look after their children at home. but B. while C. because D. though 典例1 He was about halfway through hi