The accusative case is a grammatical term used to indicate the direct object of a verb in a sentence. In languages that use cases, such as German or Latin, the accusative form shows who or what is directly affected by the action. For example, in the sentence "I see the dog," "the dog" is in the accusative case because it is the object being seen. In English, the accusative is often represented by pronouns. For instance, in the sentence "She gave him the book," "him" is the accusative pronoun referring to the person receiving the book. Understanding the accusative case helps clarify sentence structure and the relationships between different parts of speech.