There are three different kinds of conjunctions -- coordinating, subordinating, and correlative -- each serving its own, distinct purpose, but all working to bring words together.
Unlike coordinating conjunctions, subordinate conjunctions can often come first in a sentence due to the nature of the relationship between the dependent and the independent clause.
Interjections in English express strong emotions, such as love, hate, surprise, happiness, anger, enthusiasm, disgust, boredom, confusion, or unhappiness.
Examples of Subordinating Conjunctions Used in Sentences include: Because, Until, As, I know, I must, As I write this letter, I know I must say goodbye.