Pronouns are words that replace nouns. Examples of pronouns include:
* I, me, you, he, she, it, we, they, them, etc.
"As" is a conjunction, a word that connects words, phrases, or clauses. It can be used in several ways, including:
* Showing comparison: "She sings as well as her sister."
* Introducing a clause: "As I was walking, I saw a dog."
* Indicating function: "He works as a teacher."
Let me know if you have any other grammar questions!