A direct object is the person or thing that receives the action of a verb in a sentence. When you write “Sarah kicked the ball,” the ball is the direct object because that's what got kicked. When you say “I read three books,” the books are the direct object because that's what got read.

To find the direct object, ask yourself “what?” or “whom?” after the verb. In “The chef prepared dinner,” ask “The chef prepared what?” The answer is dinner, so that's your direct object. In “My brother called his friend,” ask “My brother called whom?” His friend is the direct object.

Not every sentence has a direct object. When you write “The dog barked” or “She laughed,” there's nothing receiving the action, so there's no direct object. But when you write “The dog chased the squirrel” or “She told a joke,” now you have direct objects: the squirrel and the joke.

Understanding direct objects helps you write clearer, stronger sentences. It also helps when you're learning other languages, since many languages change the form of words depending on whether they're direct objects or not.