]M2Public_holidays_Unit1.ppt

时间状语从句 Since since表示自……以来。表示动作从过去某一点时间一直延续到说话时间为止。主句中通常为延续性动词的现在完成时，since从句中一般用短暂性动词的一般过去时。 eg. It has been just a week since we arrived here. 我们到这儿刚刚一星期。 Where have you been since I last saw you? 自上次我见过你之后，你去了哪里？ Since she was young, she has been collecting stamps. 她自年轻时起就一直集邮至今。 时间状语从句 till, until 1．Until/till用于肯定句时，表示直到…为止，主句必须为持续性动词。 eg. We shall wait until/till he comes back. 我们将一直等到他回来。 Everything went well until/till that accident happened. 直到发生那意外之前，一切都正常。 2． not…until/till表示直到…才，主句通常要用短暂动词，这时until和till可用 before代替。 eg. I didnt leave until / till before she came back. 直到她回来，我才离开的。 People do not know the value of their health till until before they lose it 人们直至失去了健康才知其可贵。 3．当not until位于句首时，主句中的主语、谓语要使用倒装语序。 eg. Not until she stopped crying did I leave. 直到她不哭了，我才离开的。 4. 在强调句型中一般只用until,不用till eg. It was not until she took off her dark glasses that I recognized her. 时间状语从句 whenever whenever是when的强势语，它描述的不是一次性动作，而是经常发生的习惯性动作。 eg. You are always welcome whenever you come. 无论你何时来都欢迎。 Whenever we met with difficulties, they came to help us. 每当我们遇上困难的时候，他们就来帮我们。 时间状语从句 as soon as as soon as...可译为一……就……，用来表示主从句的动作是紧接着发生的。 eg. He will come and see you as soon as he can. 他一有空就来看你。 He rushed home as soon as he got the good news. 他一得到这个好消息就奔回家。 时间状语从句 Attention:在时间状语从句中，不能用一般将来时、过去将来时态或将来完成时，而要用相应的一般现在时态、一般过去时或现在完成时来代替。 eg.　　I’ll telephone you as soon as I get there. 我一到达那里就打电话给你。 　　 Don’t get off the bus until it has stopped. 等车停稳后才下车。 If I get up late, I will be late for school. If I don’t finish my homework, I won’t go to bed. 由if引导的从句叫条件状语从句，if意为“如果”若主句是一般将来时，从句要用一般现在时。 If you join the band, you will be famous. =You will be famous if you join the band. Homework W