Here's why:
* Pronouns replace nouns. Examples: he, she, it, they, this, that.
* Determiners modify nouns, indicating quantity, possession, or specificity. Examples: a, an, the, some, any, many, few, my, your, his, her, its.
"None" functions as a determiner because it indicates the absence of something:
* "None of the students were present." ("None" modifies "students")
* "There is none left." ("None" modifies "left")
Let's break down the other categories you mentioned:
* Demonstrative pronouns: point to specific things (this, that, these, those).
* Indefinite pronouns: refer to unspecified things (someone, anyone, everybody, nothing).
* Interrogative pronouns: ask questions (who, what, which, whom, whose).
* Relative pronouns: connect clauses (who, whom, whose, which, that).
Let me know if you have any other grammar questions!