is this a preposition

No, “this” is not a preposition. It is a determiner, pronoun, or adjective, depending on how it is used.

Uses of “This”:

1. As a Determiner (Modifies a noun to specify a particular thing)
   • This restaurant has great reviews.
   • I love this new menu.
2. As a Pronoun (Refers to something already mentioned or understood)
   • This is my favorite dish.
   • I didn’t expect this to happen.
3. As an Adjective (Describing a specific thing close in time or space)
   • She arrived this morning.
   • Let’s meet this evening.

Why “This” Is Not a Preposition

• Prepositions (e.g., in, on, under, about) show relationships between words in a sentence.
• “This” does not establish relationships; it functions as a determiner, pronoun, or adjective.

Thus, “this” is not a preposition.