從屬連詞從屬連詞是用來引導從句的。
1.連詞that, if, whether，連接代詞what, which, who, whom, whose以及連接副詞how, when, why, where可用來引導名詞從句，充當主語、表語、賓語等。非正式文體中的賓語從句常省略that：
I think (that) he’ll be back in an hour. 我認爲他一小時後就會回來。
Who they are doesn’t matter much. 他們是誰沒什麼大關係。
Can you tell me where he is? 你能告訴我他在哪兒嗎?
He asked me if/whether I knew John. 他問我是否認識約翰。
此外，that, which, who, whom, whose, when, why, where等還可以引導定語從句。
2.連詞when, while, before, after, till/until, since, as soon as等引導時間狀語從句：
She said hello to me when she saw me. 她看到我的時候，和我打了招呼。
I’ll wait here until you come back. 我將在這裏等你回來。
3.連詞if, unless引導條件狀語從句;because, as, since引導原因狀語從句：
I’ll help her if she asks me to. 如果她要求我，我就幫助她。
I won’t help her unless she asks me to. 除非她要求我，否則我不會幫她。
He didn’t come because he was ill. 因爲他病了，所以沒來。
As he hasn’t appeared yet, we shall start without him. 既然他還沒有出現，我們就先開始吧。
Since everybody is here, let’s begin. 既然大家都到了，咱們就開始吧。
4.連詞in order than, so that引導目的`狀語從句;so…that…引導結果狀語從句：
I locked the door in order that we might continue our discussions undisturbed. (=I locked the door in order to continue our discussions undisturbed.) 我把門鎖上了，以便我們可以繼續討論而不受打擾。
The car ran so fast that I couldn’t see who was in it. 汽車跑得那麼快，我沒看清誰坐在裏面。
5.連詞than, as…as…, not as/so…as…用來引導比較狀語從句：
He is better educated than his brother. 他比他兄弟受的教育好。
He is as well educated as his brother. 他和他兄弟受的教育一樣好。
He is not as/so well educated as his brother. 他沒有他兄弟受的教育好。
6.連詞although, though 引導讓步狀語從句;where, wherever 引導地點狀語從句：
I’ll go wherever you go. 不管你去哪兒，我就去那兒。
Stay where you are! 原地別動!
Though/Although she is rich, she’s not happy. 儘管她富有，但她並不幸福。
一般來說，連詞性質的連接詞連接兩個分句或引導一個從句，兩個分句或主從複合句之間用逗號連接。
