1）主语从句（subject clause），如：
How this happened is not clear to anyone. 这件事怎样发生的，谁也不清楚。
That we shall be late is certain. 我们将迟到是确定无疑的了。

2）表语从句（predicative clause），如：
The trouble is that I have lost his address. 麻烦的是我把他的地址丢了。
That is what he meant. 这就是他的意思。

3）宾语从句（object clause），如：
The seller demanded that payment should be made within five days. 卖方要求五日内付款。
She asked me which I liked best. 她问我最喜欢哪一个。

4）定语从句（attributive clause），如：
A man who sells books in a shop is called a bookseller. 开店售书的人叫书商。
The man who I saw is called Smith. 我见到的那个人名叫史密斯。

5）状语从句（adverbial clause），如：
A telegram came after you had gone. 你走后来了一封电报。
The house stood where three roads met. 这栋房子座落在三岔路口。
If she asks me, I’ll tell her. 如果你问我，我就回答她。
So far as I know, he is trustworthy. 就我所知，他是值得信任的。

6）同位语从句（appositive clause），如：
The fact that the money has gone does not mean it was stolen. 那笔钱不见了这一事实并不意味着是被盗了。
The suggestion that the new rule be adopted came from the chairman. 采纳新规则的建议是主席提出的。摘自：51talk英语角