連接詞主要分為兩種

1.      從屬連接詞 : 又稱「附屬連接詞」。以從屬連接詞所引導的從屬子句與主要子句結合形成為一個複句。從屬子句在某種程度上是用來修飾主要子句，它與主要子句相同都有主詞，但主要子句可單獨存在，從屬子句卻無法單獨存在，它必須依靠主要子句，所以才有「從屬」這個名稱。常見的從屬連接詞有

2.      對等連接詞 : 是用來連接句子中的字、片語或子句。這種連接詞所連接的兩端必須是對等的；「字」和「字」、「片語」和「片語」或「子句」和「子句」。

從屬連接詞有已下這幾種

時間        after, before, as soon as, while, when, as, by the time, since, until, once, as long as, whenever

Ex: By the time he arrived, the meeting had already ended.

Ex: Whenever I see her, I say hello.

原因        as, because, since, now that, as long as, so that, in order that

Ex: Since I am not interested in classical music, I decided not to go to the concert.

條件        if, provided that, unless, only if, even if, in case that, whether or not

Ex: I will give you my cell phone number in case you need to get in touch with me.

讓步        although, though, even though, whereas

Ex: Although the weather was cold, we went swimming.

相關        which, who, that, where, whose

參考資料: 實用基礎文法、上課講義