When is me used as a pronoun?

The personal pronoun 'me' is used to take the place of a singular noun (name) or pronoun for the person speaking as the object of a verb or a preposition.

Examples:

The boss called me to authorize the expense. (direct object of the verb 'called')

Mom made me some cookies. (indirect object of the verb 'made')

James is going to the mall with me. (object of the preposition 'with')

The corresponding singular, personal pronoun that is used as a subject is I.

Example: I called James to go to the mall with me.