The passive voice is used when an action occurs and the doer of the action is omitted; for example, The letter was written. There are two passive constructions in Spanish.

Passive voice with ser + past participle

The conjugated form of ser + past participle is used when the doer of the action is present in the sentence. This construction of the passive voice is nearly identical to the English construction. Since the past participle is considered an adjective in this construction, it must agree in number and gender with the subject.

Las cartas fueron entregadas por el cartero.

The letters were delivered by the mailman.

Aquel soldado fue admirado de todos.

That soldier was admired by all.

Los crímenes serán investigados por la policía.

The crimes will be investigated by the police.

Las casas son pintadas por el dueño una vez el año.

The houses are painted by the owner once a year.

Note: Verbs that express feeling, such as querer, amar, and admirar require the preposition de rather than por:

Juanita es admirada de todos.

Juanita is admired by everyone.

Passive voice with se:

A common way to form the passive voice in Spanish is by using the reflexive pronoun se with the third person singular or plural of the verb. This construction is most common when the person by whom the action is carried out (agent) is unimportant and not specified.

Se venden corbatas en aquella tienda.

Ties are sold in that store.

Se ve el mejor monumento en el centro del pueblo.

The best monument is seen in the center of town.

This construction is also used to convey an indefinite subject.

Se dice que él está enfermo.

It is said that he is sick.

Se oye que la situación es mejor.

One hears that the situation is better.

Se cree que es muy fácil.

It is believed that it is very easy.

Se can also be used to convey the general subject one, they, and people.

Aquí se habla español.

Spanish is spoken here.

One speaks Spanish here.

They speak Spanish here.

People speak Spanish here.