引导连词有when，while，till，not…until，since，after ,before ,as soon as
The bus won’t start until everybody gets on.
When he knocked at the door I was cooking.
Last night before he came back home, his wife had already cooked dinner and waited for 2 hours.
After I went to church, I went shopping.
地点状语从句通常由where, wherever 引导。
Where there is a will, there is a way. 哪里有志向，哪里就有出路。有志者事竟成。
Where there is a life, there is a hope. 哪里有生命，哪里就有希望。 留得青山在，不怕没柴烧。
Wherever you go, whatever you do, I will be right here waiting for you.
He didn′t see the film because he had seen it.
They couldn’t get on the train，for it was too crowed.
比较：because, since, as和for
I didn't go, because I was afraid.
Since /As the weather is so bad, we have to delay our journey.
He is absent today, because / for he is ill.
He must be ill, for he is absent today.