The possessive pronoun my is used as an adjective. It modifies a noun and shows ownership.
This is my dog.
I lost my coat.
The word mine is also a possessive pronoun. The word mine is used in place of a noun to show ownership.
The dog is mine.
The coat is mine.
The words my and mine both show possession. The word my is used as an adjective. The word mine stands alone as a pronoun.
▶Now you try it. Decide if you should use my or mine in the blank. I need to look for ____ cat. Did you use the word that modifies a noun? Good for you!