状语从句知识点讲解
定义：在句中作状语的从句叫状语从句，修饰主句中的谓语局部。
考点：状语从句有九种，其主要考点为各类连接词，理解句子即可。
一、时间状语从句
(1) when/while/as
1)when引导的时间状语从句意为“当・・•时候”，表示从句和主句的动作先后或者同时发生。从句中的谓语动词可以用短暂性动词也可以用延续性动词。
例如：When the teacher came in, we were talking.
When I first arrived on this country, I had nothing.
2)While引导的时间状语从句意为“当…时候二表示从句和主句的动作同时发
生。从句中的谓语动词必须用延续性动词。
例如：I was sleeping while Tom was watching TV.
3)as弓|导的时间状语从句意为“一边…一边”，强调主句和从句的动作同时发生。例如：She sang as she worked.
练一练：
1.you came in, I was talking with a few boys.
1.1t started to rain we were playing outdoors.
3.They talked they walked down the river.
4.it was raining, the students were playing basketball.
5.Tom watched TV he ate supper.
(2)before指主句的动作发生在从句的动作之前。
after指主句的动作发生在从句的动作之后。
例如：I'll be backbefore.你离开之前我就会回来。
What will you do after you graduate?你毕业之后想要干什么？
(3)since引导的时间状语从句，从句的谓语动词通常为一般过去时，主句的谓语动词通常为现在完成时
例如:He has been worried since the letter arrived.自从收到信,他就一直很担忧。
(4)till和until同义，意为直到，till多用于非正式文体，until多用于句首;其主句的谓语通常是延续性动词。当主句的谓语是短暂性性动词时，通常用否认形式, 即not until,意为直到…才。、
例如：He waited until she had finished speaking.
I won't go with you untill finished my homework.
(5)as soon意为一…就，表示从句的动作一发生，主句的动作立马就发生。例如：As soon as we get there, he will tell us the news.我们一到那，他就会告诉我们那个消息。
二、条件状语从句
(1)if引导的条件状语从句意为如果。
例如：Ifl were you, I'd start looking fbr another job.
(2)unless意为除非，相当于if...not。
例如：I sleep with the window open unless it's really cold.
(3)as long as意为只要
例如：We'll go as long as the weather is fine.
注意:含有时间和条件状语从句的复合，需遵循主将从现的原那么。
例如：I'll tell you everything when I come back.
练一练：
1.Til ring you up as soon as I (get) to New York.
2..1 will tell him everything when he(come) back.
3.He won't believe it until he(see) it with his own eyes.
4.一Shall we go climbing the hill this weekend?
——Good idea! We will go climbing if it.
A. wasn9t raining
B. isn,t raining
C. doesn't rain
D. won't rain
5.-Could you ask him if he to my birthday party next Sunday?
-I will, if I him this afternoon?
A. comes; meet
B. will come; will meet
C. comes; will meet
D. will come; meet
三、地点状语从句
常用where 弓【导，例如：The bus will take you where you're going.
四、原因状语从句
常由because, since, as引导。because引导的从句语气最强，since比because弱，as 的语气最弱，附带原因和理由。
例如： The food taste great because I am so hungry.
Since no one is against it, we'll do that.
As you were go out, I left a message.
