Here's why:
* Prepositions show the relationship between a noun or pronoun and another word in the sentence. They often indicate location, direction, time, or manner. Examples: in, on, at, to, from, with, by, etc.
* Determiners specify the noun or pronoun that follows. They can indicate quantity, possession, or definiteness. Examples: a, an, the, some, any, many, few, etc.
In the sentence: "Do you have any questions?"
* "Any" modifies the noun "questions," specifying an unspecified quantity of questions.
Let me know if you have any other questions!