We use the passive when we don’t know, or it isn’t important, who does the action. The passive is much more frequently used in English than in Spanish.
El passivevoice se usa cuando quieras enfatizar que se ha hecho una acción en vez de quien realiza o hace una acción.
To understand the Passive Voice we need to fully understand the Active Voice
In sentences written in active voice, the subject performs the action expressed in the verb; the subject acts. Most of our sentences are in active voice.
En el active voice el sujeto hace laacción
Active voice example:
Carlos writes a letter.
(We know who the subject is - the subject is: the noun, noun phrase, or pronoun in a sentence or clause that denotes the doer of the actionor what is described by the predicate- it is WHO does the action in this case CARLOS)
In what tense is this sentence? Yes, it is present simple.
What are the to be forms of the present simple?Yes, am is and are
The passive voice
To form the passive we need to emphasize the object and NOT the subject. To do this we need the verb to be (of the correct tense) and the past participle.form of "to be" + past participle = passive voice
Therefore; for the sentence "Carlos writes a letter" We want to focus on the letter and not Carlos
The letter is written (byCarlos). Wh y is? Well, the letter is "it" and it goes with is. We use is because the sentence is in present tense so we need the correct form of the to be in the present tense.
More examples:Present simple
She types the letters >>>>The letters are typed
She is typing the letters>>>>The letters are being typed
Present perfect simpleShe has typed the letters>>>>The letters have been typed
She typed the letters>>>>>The letters were typed
She was typing the letters...