Here's why:
* Noun: A noun is a word that names a person, place, thing, or idea. "Nut" refers to a type of food (like almonds, walnuts, etc.) or a small, hard object.
* Pronoun: A pronoun replaces a noun (e.g., he, she, it, they). "Nut" doesn't replace a noun; it's the noun itself.
Let me know if you have more questions about parts of speech!