No, “an” is not a preposition. It is an article, specifically the indefinite article used before words that begin with a vowel sound.
Function of “An” as an Article:
- Indicates a non-specific noun (singular, countable)
- She ordered an appetizer.
- He installed an updated POS system.
- Used before words that start with a vowel sound (a, e, i, o, u)
- She is an expert in restaurant marketing.
- He had an idea for a new menu item.
Why “An” Is Not a Preposition
- Prepositions (e.g., in, on, under, about) show relationships between words.
- “An” does not indicate a relationship; it modifies a noun, making it an article.
Thus, “an” is an article, not a preposition.