原因状语从句
25. 主句+in case+从句. 以免……
I will take my raincoat in case it rains. 我要把雨衣带上以免下雨。
26. 主句+due to / because of / owning to / + the fact that +从句。 由于， 因为
He did not come to school because of the fact that he was ill.
时间状语从句
27. When / While / As +从句，+主句.当……的时候
When I was in the country, I used to carry some water for you.
当我在农村时，我常常给你打水。
28. 主句+after / before +从句.
They hadn't been married four months before they were devoiced.
他们结婚不到四个月就离婚了。
We went home after we had finished the work.我们做完此工作就回家了。
29. 主语+肯定谓语+until+从句.请比较：主语+否定谓语+until+从句.
I worked until he came back.我一直工作到他回来。
I didn't worked until he came back. 他回来我才开始工作。
30. As soon as / Immediately / Directly / Instantly / The moment / The instant / The minute +从句，+主句. 一……就……
My father went out immediately I got home.我一到家，我父亲就出去了。
31. No sooner +had + 主语+done…than +主语+did.一……就……
(主语+had + no sooner +done…than +主语+did. )
No sooner had I got to Beijing than I called you. 我一到北京就给你打电话了。
= I had no sooner got to Beijing than I called you.
32. Hardly/Scarcely/ Rarely +had +主语+done…when / before + 主语+did.
(主语+had +hardly/Scarcely/ Rarely + done…when / before +主语+did. )
Hardly had she had supper when she went out. 她一吃完晚饭就出去了。
= She had hardly had supper when she went out.
33. By the time+从句，+主句.(注意时态的变化。)
By the time you came back, I had finished this book.
到你回来时，我已经写完了这本书。
By the time you come back, I will have finished this book.
到你回来时，我将写完这本书了。
34. each / every time +从句，+主句. 每当….
(这时相当于whenever 或no matter when引导的从句。从句也可放在主句之后。)
Each time he comes to Harbin, he always drops in on me.