Use of passive

Use of Passive

Passive voice is used when the focus is on the action. It is not important or not known, however, who or what is performing the action.
Example: My bike was stolen.
In the exampleabove, the focus is on the fact that my bike was stolen. I do not know, however, who did it.
Sometimes a statement in passive is more polite than active voice, as the following example shows:Example: A mistake was made.
In this case, I focus on the fact that a mistake was made, but I do not blame anyone (e.g. You have made a mistake.).
Form of Passive
Subject + finite form of to be + PastParticiple (3rd column of irregular verbs)
Example: A letter was written.
When rewriting active sentences in passive voice, note the following:
the object of the active sentence becomes the subjectof the passive sentence
the finite form of the verb is changed (to be + past participle)
the subject of the active sentence becomes the object of the passive sentence (or is dropped)

Active voiceActive voice is a grammatical voice common in many of the world's languages. It is the unmarked voice for clauses featuring a transitive verb in nominative–accusative languages, including Englishand most other Indo-European languages.
Active voice is used in a clause whose subject expresses the agent of the main verb. That is, the subject does the action designated by the verb. A sentencewhose agent is marked as grammatical subject is called an active sentence. In contrast, a sentence in which the subject has the role of patient or theme is called a passive sentence, and its verb isexpressed in passive voice. Many languages have both an active and a passive voice; this allows for greater flexibility in sentence construction, as either the semantic agent or patient may take thesyntactic role of subject.

Grammatical Rules (Reglas gramaticales)
Se forma la voz pasiva con el verbo auxiliar "to be" y el participio pasado del verbo.
Estructura Sujeto + verbo auxiliar ("to be")...