Here's why:
* Prepositions show the relationship between a noun or pronoun and another word in the sentence. They often indicate location, direction, time, or manner.
* Interjections are words or phrases that express strong emotions and are usually followed by an exclamation point.
* Conjunctions connect words, phrases, or clauses.
Example:
* "The cat walked through the door." ("Through" shows the direction of the cat's movement.)
Let me know if you have any other grammar questions!