(共29张PPT)
Unit 7
The unknown world
Oxford English
Module 4 Discovery
Grammar
Adverbial clauses of reason原因状语从句
What is
“Adverbial clauses”
Warming-up
状语修饰动词、形容词、副词或整个句子。
当状语为句子时即为状语从句，一般可以用来表示时间、地点、原因、结果等概念。
状语从句类型
( Adverbial clauses of reason)原因状语从句通常用于说明事情发生的缘由，常见的引导原因状语从句的从属连词有because, as, since等。
原因状语从句
时态：原因状语从句一般都是根据实际情况选用适当的时态。通常是主过从过，主现从现。
具体来说：
★because语气最强，可以位于句首或句中，表示直接的原因，强调他人未知的事实。回答why提出的问题时，通常用because引导的句子来回答。如：
---Why do you stop there,Eddie
---Because I have found something more pleasant than art.
★ 表示明显或已知的理由时，通常用as/since引导原因状语从句，二者语气比because弱。如：
You don’t have to see him today as you are too busy.
由于你太忙了，今天就没必要去看他了。
Since you have finished your work, you can have a rest.
既然你已经做完了你的工作，那就休息一下吧。
★because因为/since既然/as由于引导原因状语从句时，既可以放句首，也可以放句中。
When we put the adverbial clause of reason at the beginning of the sentence, we often separate it from the main clause with a comma (,).
I didn’t go because I was afraid.
= Because I was afraid，I didn’t go .
You don’t have to see him today as you are too busy.
=As you are too busy,You don’t have to see him today .
You can have a rest since you have finished your work.
=Since you have finished your work, you can have a rest.
because因为
since既然
as由于
The police officer asked Tom some more questions about the aliens. Match the questions with the answers. Then use them to complete the police officer’s notes with as, since or because.
b
d
a
c
1. (because) Tina was sure that something landed in the forests near the hills because she heard a loud noise last night.
2. (as) Tom and Tina hid behind some bushes as they heard some voices speaking a strange language.
4.(Since) Tom’s father refused to believe him since no one else saw these aliens.
3. (Because) Tom ran away because an alien saw them and made a terrible noise.
Answers
because用法
(1)because“因为”表示直接的原因或理由，语气最强，通常放在主句之后，有时也放在主句之前。
I stayed at home because it rained.
(2)回答why提出的问题，只能用because。
— Why didn’t you call me last night
— Because I didn’t want to disturb you.
(3)because(因为)和so(所以)不能一起使用。
Because it was raining, we stayed at home.
=It was raining , so we stayed at home.
中考题小练
1. I hate travelling by air _____ you usually have to wait for hours before the plane takes off. ( 上海市)
A. because B. though
C. until D. unless
2. — _____ is the street crowded with so many people
— Because they are waiting to watch the boat races. ( 湖北宜昌)
A. Why B. Where C. How D. Who
because相关
1.because引导的从句可用于强调句，其余不 能。
It’s because he is kind that we like him.
2.because从句可用作表语(be动词后)，其余不能。
This is because the earth is traveling around the sun.
3.表示“……的原因是因为……”这一意义时，一般要用The reason why…is that…
The reason why he cannot come is that he is ill.
他不能来的原因是他生病了。
注意：
since用法
一般表示对方已知的、无须加以说明的既成事实的理由，全句中心在主句，语气比because弱，常译为“既然”。引导的从句常放在句首。
Since you are free today, you had better help me with my math.
既然今天你休息， 你最好帮我补习数学。
since可用于省略句，而其它不能。如：
Since so, there is no more to be said.
注意：
1. _______ he takes exercise every day, ______ he is very healthy.
A. Because; so B. Although; but
C. Because; / D. Although; /
2. — What shall we do this afternoon
— _____ it’s very cold, let’s stay at home.
A. While B. Since
C. Until D. After
as用法
as 引导的原因状语从句时表示附带说明的“双方
已知的原因”，语气比since弱，较为正式，位置
灵活（常置于主句前）。
As it is raining, you’d better take a taxi.
既然在下雨， 你最好乘出租汽车。
I went to bed early, as I was exhausted.
我睡得早， 因为我筋疲力尽了。
1. ______ you are leaving tomorrow, we can eat dinner together tonight.
A.For B. Since C. Before D. Whil
2. _____ the weather was fine, I opened all the windows.
As B. Because of
C. For D. With
1. because 意为__________
2. because 语气_______, 表示_________ （直接or间接）原因
3. because 常用来回答__________引导的疑问句。
4. because 常放在_______。
Work out the rule：
因为
最强
直接
why
句中
注：because不能与so连用。
Summary
Work out the rule:
since 意为_______________, 表示对方已知
的事实或显然的理由, 语气比because_____,
引导的从句常放在_________。
2. as 意为___________，表示明显的原因
或已知的事实，语气比since _______, 引导
的从句常放在________。
既然，由于，因为
弱
句首
由于，因为
弱
句首
注：since与as用法大致相同,且都
不能与so连用。
用because , since和as填空
I didn’t go to school yesterday ________
I was ill.
2. ________ everybody is here , let’s begin our
meeting.
3. ________ you are in poor health, you should not
stay up late.
4. I asked her to stay nearby __________ I had
something to tell her .
5. ________ all the passengers are here, why don’t
we start at once.
6. Bill won’t make any progress __________ he
doesn’t study harder than before.
because
Since/As
Since/As
because
Since/As
because
because of
because of是固定短语，后接名词，动名词(Ving)或名词性短语。表示“由于”，“因为”。它可引导介词短语作表语，也可引导短语作状语。
I went to the party because of him.
因为他，我去参加了聚会。
This boy didn’t do his homework because of skating.
这个男孩因为滑冰而没有做家庭作业。
拓展：
We can use a noun, a noun phrase or a (subject pronoun/object pronoun) after because of.
如：
I was late because the traffic was heavy.
因为交通拥挤，我迟到了。
= I was late because of the heavy traffic.
He can’t go to school because of illness.
他因病不能上学。
= He can’t go to school because he is ill.
★有时because和because of可以相互转换。
because; because of
1. He walked slowly _________ his bad leg.
2. _______ I don’t complain, the manager thinks I’m pleased with their service.
3. All flights have been put off _________ bad weather.
because of
because of
Because
Write sentences about the story on page 99 by using because of .
1.Tina was surprised because of the yellow light in the sky.
2.The aliens landed on this planet because of an accident.
Answers
3.The children ran away from the forest because of the aliens.
4.Their dad was not sure about the children’s story because of the writing on the piece of paper.
（2016 大庆）Zootopia，the cartoon，is popular ___________there are many lovely animals in it．
A.though B．because C．if D．because of
中考链接
【解答】答案：B；though虽然；because因为，是连词，其后接原因状语从句或回答以why开头的问句；if如果；because of因为，是复合介词，其后接名词、代词或动名词；根据句意可知，there are many lovely animals in it是Zootopia，the cartoon，is popular的原因，因为there are many lovely animals in it是从句，故用because引导；故选B．
（2016 无锡）
Could you help me with housework _________ you are free today？
A．since B．though
C．unless D．until
【解答】答案：A；
根据设空处前的句意"你能帮我做家务吗？"和后面的"你今天有空"可以推测选项中的since可以把连个句子连起来，构成句子的句意是"既然你今天有空，你能帮我做家务吗？"，表示"既然"用since；故选A
