Eg: -Why are you late? -Because my car is broken. As it’s raining,we should stay here. You can’t see the teacher,for he isn’t in.
Since you can’t answer this question, I will call others.
1.when,while,as “当…时”
When he came in, I was cooking. 他进来时，我在做饭。 He came in while I was cooking. She sang as she worked. 一边……一边…… When + 短暂性动词（常+一般过去时） While + 持续性动词（常+过去进行时） As 动作衔接紧密，表“伴随”
状 语 从 句 讲 练
状语从句可以根据其用途分为：
时间状语从句、地点状语从句、原因状 语从句、结果状语从句、目的状语从句、 条件状语从句、让步状语从句
一 时间状语从句 一般由when，while，
as，after，before，since，until，as soon as等从属连词引导。
当主句是一般将来时或祈使句，表示 将来的意义时，从句用一般现在时。
ቤተ መጻሕፍቲ ባይዱ
because like them. 5. I eat potatoes _________I 我吃土豆是因为我喜欢土豆。 6. ____I As didn’t know the way, I asked a policeman. 我由于不知道路，因而问警察。 Since 7. _______you won’t help me, I’ll ask someone else. 你既然不帮我，那我就请别人帮我。
3.since “自从”（常用于现在完成时） 从他离开后我们没见过面。 We haven’t seen each other since he left.

4.as soon as”一…就…” 我一回来就给你打电话。 I’ll call you as soon as I come back. 主将 从现
注：
★because of和because的区别
① because of后加名词代词或动名词， 不加句子，而because加句子，例：
Because
of his illness, he didn’t go
to work. 因为生病，他没上班。 Because he was ill, he didn’t go to work.
主将从现
when before as soon as not…until

二. 地点状语从句
地点状语从句由where, wherever等引导。例 如： •Where there is a will,there is a way. • You can take a walk wherever you like to.
2. before 在……前 It will be half a year before I come back. I had finished my homework before my father came back.
After 在…之后 After I had finished my homework,my father came back.
Because 1. _________he was ill, he didn’t go to school. Since 2._______ you do not understand, I will explain again. As 3. ____she was late for class, she had to say sorry. for 4. He must be ill, _____he is absent today.
※while 的其他含义： While I was walking down the street, I came when across an old friend. ( while =_______) He likes pop music, while I am fond of folk but music. ( while =_______)

5.not…until “直到…才…” 我将不会离开直到他回来。 I will not leave until he comes back. 主将 从现 I did not leave until he came back.

When he comes here tomorrow, I will 1. ______ call you. 2. While/When ________ he was walking in the street, he met Tim. 3. She sang ____she worked. as as soon as 4.I ’ll ring you up _____________I get to Beijing.
5.It won’t be long ______he finishes his before writing. 6.______ After he had finished his work, he left there. since 7.It is two years ______he came here. Until 8. _______she told me, I had no idea of what they had said .
三 原因状语从句 通常由
because,since,as,for 引导 所表示的语气由 because>since>as>for逐渐减弱。
because表直接原因,有很强的因果关系,回答 “why”的 提问，since表很明显的原因,“既然”常放句首，as表 明显原因，语气较弱。for放句中，补充说明原因。