原因状语从句
(1)原因状语从句：从句表示的是主句行为的原因。通 常由because, since, as, for引导。 (2) because表示直接原因（听话人所不知的），语气最强。 回答由why提出的问题，只能用because。此外， because和so不能同用在一个句子里。
例如：--Why aren’t going there? --Because I don’t want to.
to… eg. He got up early to catch the early train.
in order that …
eg. He got up early in order that he could catch the early train.
in order to… eg. He got up early in order to catch the early train.
目的状语从句
目的状语从句: 从句表示的是主句行为的目的 (1)通常由 so that, in order that（为了，以便）引导。 例: We started early so that we could catch the first train. We used the computer in order that we might save time.
since 相当于now that，“因为…，既然…， 鉴于…” 表示显然的或已为人知的理由，语气较because弱
例如：Since the rain has stopped，let’s go for a walk. 既然雨停了，我们出去散散步吧。
as和since语气较弱，一般用来表示明显的原因。 由as和since引导的原因状语从句多放在句首。 例如 ：As he has no car, he can’t get there easily. Since we have no money, we can’t buy it.
something wrong with my bikbee. cause 2. He took off his coat _______ he felt hot. 3.________you can’t anfsowr er the question, I’Allsa/skinscoemeone else.
(2)so that可引导目的状语从句，此时可用to或in order to 替换,将其改为简单句。 例如：
He got up early so that he could get to school on time. =He got up early（in order） to get to school on time.
判断以下句子是目的状语从句还是条件状语从句？
练习： 1. I hurried _s_o__th_a_t__I wouldn't be late for class. 2. We should go by bus __s_o_t_h_a_twe can get there earlier.
3. May I sit nearer__s_o__th_a_t_ I can see more clearly?
Mother lives so far away that we hardly ever（几 乎不，从来不） see her.
（2）在由such…that引导的结果状语从句中，such 是形容词，它修饰的可以是单数或复数可数名词，也 可以是不可数名词；其结构是: “...such +a / an + 形容 词+名词+ that + 从句”。 例如： 1.It was such a hot day that nobody wanted to do anything. 2.He had such long arms that he could almost tou ch the ceiling.（天花板）
（3）so that既可引导目的状语从句，又可引导结果状 语从句。区别这两种从句的办法有两个：
A)目的状语从句里往往带有情态动词 can, could, may, might等。
B)从意思上看，目的状语从句往往表示的目的很明确， 不放在句首。 例如： Speak clearly so that they may understand you. (目的状语句) Jack is badly ill so that he has to rest. (结果状语从句)
结果状语从句
(1)结果状语从句由so…that, such…that, so that引 导。
(2)so…that与 such...that可以互换。在由so...that引 导的结果状语从句中，so是副词，与形容词连用。其 结构是: “...so + 形容词（副词）+ that + 从句”。
例： He was so glad that he couldn’t say a word.
(4)for表示所说的理由是一种补充说明,for引导的从句一 般不放在句子的开头。 如: I decided to stop and have lunch, for I was feeling quite hungry. Eg: 1. I was late for class yesterday _______ there It was such a wonderful film that all of us wa nted to see it again. =The film was so wonderful that all of us wanted t o see it again.
用于目的状语从句，还有：
so as to…(肯定结构) eg. He got up early so as to catch the early train.
so as not to…(否定结构) eg. He got up early so as not to miss the early train.