講義: 一、時間狀語從句 1. when與while while引導時間狀語從句時,表示“當(在)……時”,強調during that time,while從句中常用延續性動詞或表狀態的詞。當兩個延續性動作同時發生時,用while。while引導的從句與主句之間可構成對比。 例:While I was playing the piano, she was dancing. 2. when表示“當(在)……時候”時,when相當于at that time或during that time,既指時間點,也可指一段時間,引導的從句可用瞬間動詞,也可用延續性動詞(相當于while) ;與主句所表達的動作有先后,也可同時進行。 例:Jim was reading when the teacher came in. 3. until“直到”,表示某行為一直持續到某一時間,用在肯定句中,句子的謂語動詞必須是延續性的。not...until“直到……才”,表示直到某一時間,某一行為才發生,之前該行為并沒有發生,用在否定句中,主句中的謂語可以是延續性動詞也可以是短暫性動詞。 例:I didn't go to bed until my father came back. I studied English until 9 o'clock last night. 4. 由as soon as (=the moment)引導的時間狀語從句表示“一……就”。 二、原因狀語從句 1. 引導原因狀語從句的連詞 原因狀語從句一般由從屬連詞because, as, since, now that引導。 2. because, as, since和now that的區別: because“因為”,表示直接的原因,語氣最強。why提問的句子,必須用because回答。because從句常放在主句之后。because 不能與so連用。because后跟從句,because of后跟名詞或名詞短語。 例:I did it because he told me to. as“因為”,語氣較弱,一般放在主句前,中間用逗號隔開,表示的是明顯的原因。 例:Enjoy the first hour of the day. This is important as it sets the mood for the rest of the day. since/ now that “既然”,一般放在主句前,中間用逗號隔開,表示的是明顯的原因或眾所周知的事實。 例:We thought that, since we were in the area, we'd stop by and see them. 3. for 引導的并列句與原因狀語從句的辨析 并列連詞for意為“因為”,引導的不是從句,而是并列分句,只能放在主句之后,不能放在句首,常用逗號把它和前面的分句隔開,對主句補充說明理由或推斷原因。 例:I believed her, for surely she would not lie to me. |
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