Here's why:
* Nouns name people, places, things, or ideas.
* Verbs express actions or states of being.
* Adjectives describe nouns or pronouns.
While some words can be both nouns and verbs (like "run"), or nouns and adjectives (like "gold"), it's rare to find a single word that functions in all three ways.
Let me know if you'd like to explore some examples of words with multiple functions!