一、状语从句
状语从句是指在整句中作状语时，起副词作用的句子。它可以修饰谓语、非谓语动词、定语、状语或整个句子。根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式和比较等从句。状语从句一般由连词（从属连词）引导，也可以由词组引起。
二、原因状语从句
如果从句表示的是主句行为的原因，就构成原因状语从句。原因状语从句由表示原因的连词引导，常用的有because，since，as等。
1.because引导的原因状语从句，表示的往往是读者不了解的、不明显的原因，是全句叙述的重点，语气最强。because引导的原因状语从句既可以放在主句之前，用逗号隔开，也可以放在主句之后。如：He failed the exam because he was too careless.
2.since引导的原因状语从句，表示显然的或已为人知的理由，常译为"因为；既然"。如：
Since everyone is here，let's start our meeting.
3.as引导的原因状语从句，意为"因为；由于"，其语气不如because强，通常为附加说明的理由，且是已知晓的原因，主句与从句没有逻辑上的因果关系。如：As she wasn't well, I went there alone.
三、结果状语从句
如果从句表示的是主句行为的结果，就构成结果状语从句。结果状语从句由表示结果的连词引导，常用的有so，so...that...,such...that...等。
1.so引导的结果状语从句，表示"由于某个行为而导致的结果"，只能放在主句之后。如：
He worked too hard, so he fell ill again.
注意：because和so不能同时用在一个句子里。如：Because it rained heavily, we stayed at home./It rained heavily, so we stayed at home.
2.so...that...引导的结果状语从句，意为"太......以致于......"，so后面接形容词或副词（看so前面的词来决定用形容词还是副词，如果是系动词就用形容词；如果是行为动词，就用副词。），表示程度，that后接从句表示这一程度造成的影响或结果。如：
He is so young that he can't go to school./He speaks so fast that I can't understand him.
3.such...that...引导的结果状语从句，意为"太......以致于......"，such后面接（1）such a/an 形容词 可数名词单数=so 形容词 a/an 可数名词单数（2）such 形容词（除many,much,little,few外，如果是这四个形容词时，such要换成so） 可数名词复数或不可数名词，that后接从句表示这一程度造成的影响或结果。如：She is such a kind girl that everyone likes her./It is such fine weather that we all want to go for a walk.
四、目的状语从句
如果从句表示的是主句行为的目的，该从句就是目的状语从句。目的状语从句由so that，in order that等引导，so that或in order that引导的目的状语从句中常常含有表示可能性的词语，如could，will，would或can等。如：I got up very early so that/in order that I could get to school on time.
五、练习
（一）根据句意，用合适的连词填空，使句子意思完整。
1.The girl was happy_____her friends gave her beautiful presents.
2._____we are students, we must study hard every day.
3.He got up_____he could catch the first bus.
4.The box is_____heavy_____the little boy can't carry it.
5.He was_____a helpful boy_____everyone likes him very much.
6.They are_____beautiful flowers_____we want to take photos of them.
7.The boy runs_____fast_____we can't catch up with him.
8.There were few doctors then, _____he had to work hard on his own.
9.I have been there twice, _____I don't want to go again.
10.We study hard_____we can have a good future.
（二）句子翻译。
1.她努力训练，所以后来她成为了一名很棒的运动员。
2.她是我的英雄，因为她是世界上最好的乒乓球运动员之一。
3.你必须现在走，这样你上学就不能迟到。
4.咖啡太热了，以致于我现在不能喝。
5.他是如此小的男孩，以致于他不能照顾自己。
6.因为昨晚天太热，大家都待在树下。
7.既然我们没有钱，我们就不能买这座房子。
8.她如此兴奋，以致于她无法入睡。
9.他们昨天没吃野餐，因为天下大雨。
10.他家离学校最远，所以他每天坐地铁上学。
*练习参考答案
（一）1.because 2.Since 3.so that/in order that 4.so that 5.such that 6.such that 7.so that 8.so 9.so 10.so that
（二）1.She trained hard, so she became a great player later.
2.She is my hero because she is one of the best table tennis players in the world.
3.You must go now so that you won't be late for school.
4.The coffee is so hot that I can't drink now.
5.He is such a young boy that he can't look after himself.
6.As it was hot last night/yesterday evening, everyone stayed under the tree.
7.Since we have no money, we can't buy that house.
8.She was so excited that she couldn't fall asleep.
9.They didn't have a picnic because it rained heavily yesterday.
10.His home is the farthest from his school, so he takes the underground to school every day./He lives farthest from his school, so he goes to school by underground every day.
