Here's why:
* Proper nouns are specific names of people, places, or things. "Titanic" is the specific name of a famous ship.
* Abstract nouns refer to concepts, ideas, feelings, or qualities that cannot be touched (e.g., love, happiness, courage).
* Collective nouns refer to a group of people, animals, or things (e.g., team, flock, herd).
Let me know if you have any other questions!