No, “they” is not a preposition. It is a pronoun.
Function of “They” as a Pronoun:
- As a Subject Pronoun (Referring to a Group of People or Things)
- They ordered food from the restaurant.
- They are working on a new menu.
- As a Gender-Neutral Singular Pronoun
- The customer said they would arrive at 7 PM.
- If a manager calls, ask what they need.
Why “They” Is Not a Preposition
- Prepositions (e.g., in, on, under, about) show relationships between words.
- “They” is a subject pronoun, meaning it replaces a noun and does not function as a linking word between words or phrases.
Thus, “they” is a pronoun, not a preposition.