Here's why:
* Nouns name people, places, things, or ideas (e.g., dog, park, book, happiness).
* Pronouns replace nouns (e.g., he, she, it, they).
* Possessive pronouns show ownership (e.g., mine, yours, his, hers, ours, theirs).
Example:
* Our car is red. ("Our" shows ownership of the car.)