课件17张PPT。Grammar 1 Adverbial clause of timeWhen 引导的时间状语从句中的谓语动词既可以是延续性动词,也可以是非延续性动词;从句的动作可以和主句的动作同时发生,也可以先于主语的动作发生。While 引导的时间状语从句中的谓语动词一般是一段较长的时间或过程,故动词必须是延续性动词,强调主句谓语动词和从句谓语动词所表示的动作或状态是同时发生或存在的。1. When he left school at fourteen, he began to train as an engineer.
2. While he was taking a walk in the street, he saw an accident.
(比较句子当中从句与主句谓语动作之间的先后关系)Compare the two sentences below before has special meanings in the adverbial clause of time, the negative form mustn’t be used in the suborning sentences led by 〝before〞, pay attention to the translation of the following sentences. 1) We had sailed four days and four nights before we saw land.
我们航行了四天四夜才看到陆地。
2) We hadn’t run a mile before he felt tired.
我们跑了还不到一英里他就累了。3)Please write it down before you forget it.
趁你现在没忘把它记下来。
4)Before I could get in a word, he had measured me.
我还没来得及插话他就给我量好了尺寸.
5) It will be half a year before I come back.
半年之后我才能回来。 since can be used in the adverbial clauses of time, much attention must be paid to the tenses used in the sentences. 1) I have written home four times since I came back.
2) It is three years since the war broke out.Grammar 2 Adverbial clause of reason---Why didn’t he come yesterday?
---Because he had something important to do.
2. Since you don’t like to do it , I’ll ask someone else.Read the sentences below carefully3. It rained last night, for the ground is wet this morning.
4. Now that you have finished your homework, you may go home now.
5. As he was tired, he went to bed early.1. 引导原因状语从句的从属连词有because, since, for 等。because所表示的原因含有很强的因果关系,用来回答why提出的问题,在强调原因时,从句可以置于主句前。---Why didn’t he come yesterday?
---Because he had something important to do.2. For 也常用来表示原因,一般用来表示补充说明辅助性理由或提供上文未交代的情况。
It rained last night, for the ground is wet this morning.3. Now that, seeing that, considering that 等也可以用来引导原因状语从句,有时可以先表示一种情况,再加以推论。 that可以省去。
Now that you have finished your homework, you may go home now.4. 如果表示已知的或是比较明显的原因,可以用as(由于)或since(既然)。
Since you don’t like to do it , I’ll ask someone else.