Here's why:
* Pronoun Case: "Me" is an object pronoun, meaning it's used when the pronoun is the *receiver* of an action. "I" is a subject pronoun, used when the pronoun is the *doer* of an action.
* Correct Structure: When you have two people involved, the sentence structure should follow the order of who is performing the action and who is receiving the action.
Examples:
* Incorrect: "Me and John went to the store."
* Correct: "John and I went to the store." (We are the subjects performing the action of going)
* Incorrect: "The teacher gave the book to me and John."
* Correct: "The teacher gave the book to John and me." (We are the objects receiving the action of giving)
Tip: A good way to check is to remove the other person's name and see if the sentence still makes sense. For example: "Me went to the store" is incorrect, while "I went to the store" is correct.