The passive voice foregrounds the action or the result, not the person who acts. It appears often in news, reports, notices and formal texts when it matters more what happened than who did it. Instead of centering the sentence on the agent, the structure highlights the fact: the door was opened, the report was delivered, the rule was approved. In that type of text, the passive gives distance and an objective tone, similar to the one also sought in Estilo and in the Voz Impersonal.

Contexts for using the passive voice

Idea
Use the passive voice when you want to highlight the action more than who performs it
Use the passive voice when the result is more important than the agent
Use the passive voice in formal texts such as news and reports

The active voice presents the subject as the one who performs the action: María wrote the email, the technician repaired the machine, the children opened the box. It is the most direct form and the one that sounds most natural in everyday conversation, because the agent is clear from the start. In Spanish, the active voice is usually the normal option when there is no need to hide or shift the subject. It also fits well with the basic organization of the Parts of the sentence, where the subject and the verb form the center of the idea.

Passive with ser uses ser + past participle. The subject of the sentence receives the action: the building was constructed in 1998, the tickets will be sold tomorrow, the letter was sent by mail. The participle agrees in gender and number with that subject: fue aprobada, fueron aprobados. This form sounds more formal than the active and is used a lot when the result is important or when the text wants to maintain an objective tone, as in press releases, news, or reports.

Structure of the passive with ser

Idea
The passive with ser uses a verb in the participle to present the result
The participle agrees with the subject of the sentence
The passive with ser sounds more formal and objective

The reflexive passive uses se + verb in third person. It does not name the agent and presents the action as general or institutional: apartments are sold, the law was approved, the documents are reviewed. The verb agrees with the subject that receives the action: bread is sold, books are sold. This construction is very common in general written Spanish and tends to sound more natural than the passive with ser in many contexts. It also appears near the Voz Impersonal, but here there is indeed a clear subject that agrees with the verb.

Use of the reflexive passive with se

Idea
The reflexive passive uses se to talk about actions without naming the agent
The verb agrees with the subject of the sentence
The reflexive passive is very common in general written Spanish

When a passive sentence mentions who performs the action, the agent is introduced with por: the house was bought by a family, the message was written by Ana, the room was cleaned by the staff. In the passive with ser, that complemento with por can appear at the end and complete the information without taking away the focus from the result. por is not used for the subject of the passive, because the subject remains the thing or person that receives the action.

The active voice is usually the best option when you want clarity and naturalness: the subject acts, the verb advances and the sentence is understood right away. The passive serves when the result matters more than the agent, when the agent is unknown, or when the tone should sound more formal. In a conversation, 'The mechanic fixed the car' sounds more normal than 'The car was fixed by the mechanic.' In a report, news, or administrative text, the passive may fit better because it shifts attention toward the fact. The choice depends on what you want to foreground: the person who does something or the action itself.

Criteria for choosing active or passive

Idea
Use the active voice when you want a sentence clearer and more natural
Use the passive voice when you want a tone more formal
Choose the voice that best fits the message to the purpose of the sentence