1、时间状语从句就是用来说明主句动作与从句动作发生时间上的先后关系。既然说到动作发生的时间，就必然与主句和从句的谓语的时态关系密切，时态又与动作的持续时间的长短，即延续动词和短暂动词有关，注意：1 注意主句，从句的时态的搭配关系。2 注意主句，从句的谓语动词的延续性和短暂性。I was telephone Harry when she arrived. 她到的时候，我正在给哈利打电话。I telephoned Harry when she arrived. 他到了之后理解思维方式till, until 用法的区别1 这两个词都可以做连词和介词。句首一般都用 until, 强调句中多用 until。
2、意为“直到(为止)” 。2 如果主句中谓语动词是瞬间动词，要用否定式 notuntil, 意为“直到才” 。3 如果主句中谓语动词是延续性动词，可用肯定式也可用否定式，但意义不同。He waited for her till 6 oclock. 他等她一直到六点钟。Until Friday I cannot go home. 直到星期五我才回家。He waited until the sun had set. 他一直等到太阳下山。He didnt go out until he finished his homework. 直到做完作业他才出去。He worked till you came
3、back. 他一直工作到你回来。He didnt work till you came back. 直到你回来他才开始工作。一，延续动词+until +短暂动词或时间点当主句或句子的谓语动词是延续动词时，until 后面若接从句则从句谓语必定是短暂动词。Wait until he comes back. 等他回来吧。Well stay here until it stops raining. 我们将一直待到雨停了再走。I will be away from my office until next Tuesday.我要离开办公室直到下周二才回来。二，短暂动词+until +短暂动词或时间点。若
4、主句或句子谓语动词是短暂动词，则要用否定形式，因为否定之后表示的是一个状态，而状态是延续的，notuntil结构。He didnt leave the office until his boss came back.直到老板回来，他才离开办公室。One will never realize how much and how little he knows until he starts talking.人们只有在与人进行交谈时才知道自己到底懂得多少。I didnt go to bed until 12 oclock last night.Notuntil 1） 正常结构 The little
5、boy didnt smile until he saw his mother. 这个小男孩看到他妈妈之后才开始笑起来。2） until 置于句首 只需要把 until 后面的所有成分提到句首，便有了 until，not 结构Until he saw his mother, the little boy didnt smile. 3) 倒装结构 部分倒装“Notuntil, 谓语助动词+主语+ 谓语动词 ”Not until he saw his mother, did the little boy smile.4） 强调结构It was not until +时间从句或短语 +that +主句部分It was not until he saw his mother that the little boy smiled.1 Yesterday, I waited for you at the bus station _4 oclock in the afternoon.2 _you told me, I had heard nothing of what happened. 3 It was not _ the result of the exam was announced that he realized he had organized time badly.
