Him is a pronoun used to refer to a male person or animal that has already been mentioned or is understood from context. When you say “I saw John yesterday, and I waved to him,” you're using him to avoid repeating John's name.

Pronouns like him keep language flowing smoothly. Without them, you'd have to say “I saw John yesterday, and I waved to John, and John waved back to John's sister,” which sounds clunky and repetitive. Instead, you say “I waved to him, and he waved back to his sister.”

Him is an object pronoun, which means it's used when someone is receiving an action rather than doing it. You give something to him, tell him a story, or ask him a question. This is different from he, which is used when the male person is doing the action: “He asked me a question.”

The word pairs with other pronouns: she and her for females, they and them for plural or gender-neutral references. Learning when to use him versus he helps your writing and speaking sound natural and correct.