The document discusses direct and indirect objects in Spanish sentences. A direct object receives the action of the verb, while an indirect object refers to someone or something that is indirectly affected by the action. Several examples are provided of sentences containing both direct and indirect objects, such as "My aunt gave my uncle an inflatable doll for Christmas." The direct object is "an inflatable doll" as it is the thing received, while the indirect object is "my uncle" who indirectly receives the doll. Certain verbs like "explain" require using "to" when followed by an indirect object.