地点状语从句
常用连词：where
特殊连词：wherever (在……的任何地方), anywhere, everywhere
【点拨】地点状语从句与定语从句的区别：where引导定语从句时，从句前应有一个表示地点的名词作先行词；而状语从句前则无需先行词。
Go back where you came from.(where引导地点状语从句)你从哪儿来回哪儿去。
Go back to the village where you came from. (where引导定语从句，修饰village)回到你来的那个村子里去。
时间状语从句
常用连词：when, as, while, as soon as, before, after, since , till, until, whenever (每当，一……就……)
特殊连词：the minute, the moment, the second, every time, the day, the instant, immediately, directly, no sooner ... than, hardly ... when, scarcely ... when 1．由when, while, as引导的时间状语从句when，while，as都有“当……时候”的意思。
1) when引导的从句的谓语动词既可以是延续性动词，又可以是瞬间性动词，并且when有时表示“就在那时”，相当于and at that time。
It was raining when we arrived. (指时间点)当我们到达的时候，天正在下雨。
When we were at school, we went to the library every day. (在一段时间内)
我们在学校上学的时候，每天都去图书馆。
We were about to leave when he came in.我们刚要离开，就在那时他进来了。
2) while引导的从句的谓语动词必须是延续性的，并强调主句和从句的动作同时发生(或者相对应)，此外，while有时还可以表示对比。
I like playing football while you like playing basketball.
我喜欢踢足球，而你喜欢打篮球。
(对比)
He fell asleep while/when reading.看书的时候，他睡着了。
Strike while the iron is hot. (用as或when不可以，这里的while意思是“趁……”) 趁热打铁。
3) as表示“一边……一边”，as引导的句子的动词是延续性的动词，一般用于主句和从句动作同时发生；as也可以强调一先一后。
We always sing as we walk.我们总是边走边唱。
(as表示“一边……一边”)
Our headmaster laughed as she spoke.我们的校长边谈边笑。
2．由before“在……之前”和after“在……之后”引导的时间状语从句。
It will be four days before they come back．他们要过四天才能回来。
My father had left for Canada just before the letter arrived.
我父亲恰好在信到之前去加拿大了。
After you think it over, please let me know what you decide.
你仔细考虑过以后，请告诉我你是怎样决定的。
3．由till或until引导的时间状语从句。
其句型：...not + until + 短暂性动词；... (延续性动词)+until...
It was not until the meeting was over that he began to teach me English.
直到散会之后他才开始教我英语。
I worked until he came back. 我工作到他回来为止。
【点拨】not until...结构的强调和倒装
It was not until she had arrived home that she remembered her appointment with the doctor. 直到她到家才想起她和医生的约定。
Not until she had arrived home did she remember her appointment with the doctor. 直到她到家才想起她和医生的约定。
4．由since引导的时间状语从句。
Where have you been since I last saw you?自上次我和你见面以后，你到哪里去了?
It is four years since my sister lived in Beijing.我妹妹不在北京住有四年了。
【点拨】since引导的时间状语从句常用一般过去时。
5．由as soon as, immediately, directly, instantly, the moment, the instant, the minute, no sooner...than..., hardly...when...等引导的时间状语从句，这些连词都表示“一……就……”。
I will go there directly I have finished my breakfast一吃完早饭我就立即到那里去。
The moment I heard the news, I hastened to the spot
我一听到那个消息马上赶到了现场。
【点拨】表示突然发生某事或紧接着发生某事，常可译为“……还没/刚刚……就……”，“正在……忽然……”或“正要……这时……”，主要用于hardly/ scarcely…when…，no sooner…than…，be doing...when...和be about to do...when...这四个句式，前两个句型主句用过去完成时，从句用一般过去时。
I had hardly opened the door when the man hit me.我刚打开门，那个人就打了我一拳。
I was about to leave the room when the telephone rang我正要离开房间这时电话响了。
6．由the first (second/last) time, next time, any time, each time, every time, whenever, all the time, the whole time等引导的时间状语从句。
Whenever that man says “to tell the truth”, I suspect that he’s about to tell a lie.每当那个人说“实话说吧”的时候，我猜想他就要说谎了。
You grow younger every time I see you.每次遇到你，感觉你更年轻了。
原因状语从句
常用连词：because, since, as, now that（既然）等，for 表示因果关系时（它引导的不是从句）为并列连词，语气不如because强。
特殊连词：seeing that, in that, considering that, given that,considering
that, in as much as, in so much as
1．because引导的原因状语从句一般放于主句之后，because表示直接原因，语气最强，常回答why引导的疑问句。
I do it because I like it.我做这件事是因为我喜欢。
2．since引导的原因状语从句一般放于主句之前表示已知的、显然的理由(通常被翻译成“既然”)，较为正式，语气比because弱。
Since you are free today，you had better help me with my mathematics．
既然今天你休息，你最好帮我补习数学。
【点拨】seeing (that), now (that), considering (that), in that这几个词汇与since 引导的原因状语从句意思相近，都表示“既然”。
Now (that) you are grown up, you should not rely on your parents.
既然你长大了，就不应该依靠你的父母了。
3．as引导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，位置较为灵活(常放于主句之前)。
As it is raining, you’d better take a taxi.既然在下雨，你最好乘出租汽车。
4．for是并列连词，连接并列句。
for引导的句子并不说明行为发生的直接原因，只提供一些辅助性的补充说明
He could not have seen me, for I was not there.
他不可能见过我，因为我不在那里。