The word on is a preposition. The words on me form a prepositional phrase. Always use the pronoun me (not I) with the preposition on.
My little sister played a joke on me.
My prom date pinned the corsage on me.
The tree sap dripped on me.
The pronoun me is used as the object of the preposition on.
If we include another person as part of the object of the preposition, we still use the pronoun me.
My little sister played a joke on my friend and me.
Our dates pinned the corsages on Susan and me.
The tree dripped sap on John and me.
The pronoun me is used as an object of the preposition – on me.
▶It’s your turn. Which of these sentences is written correctly? As we walked, the snow fell on Jim and I. As we walked, the snow fell on Jim and me. Did you choose the one that uses the pronoun me? Good for you!