When you need a pronoun for an object, use an object pronoun. Your choices are me, you, him, her, it, us, them, and whom.
Applying this tip is pretty simple, but many people make mistakes when the object contains two or more things. They may use a subject pronoun instead: I, you, he, she, it, we, they, and who. These subject pronouns cannot be used as objects, except for you and it, which are both types of pronouns.
Consider this sentence.
“Mary drove Tom and I to the house.”
This sentence is incorrect. “I” is not an object pronoun; it is a subject pronoun. The correct pronoun is me. The sentence should read as follows.
“Mary drove Tom and me to the house.”
Because most people won’t make this mistake when the sentence only has one object pronoun, you can use this trick: remove one object, say the sentence aloud, and determine if it still sounds right. Then do it with the other one.
For example, you would say “Mary drove Tom to the house. Mary drove I to the house.” The first one sounds right, but the second doesn’t. You would say “Mary drove me,” so you know the complete sentence should be “Mary drove Tom and me to the house.”