The passive voice in Persian is used when the receiver of the action in question turns into the subject of the sentence itself, completely different from the usual active voice. Interestingly enough, Persian doesn't tend to use the passive voice as much and almost always prefers the active voice. However when referring to events, the passive voice may be utilized and is important to know.
The passive voice is formed by:
Having the past participle of a verb (e.g: the past participle of sākhtan (سختن) "to build/make" is sākhte (ساخته).
Adding -e (ه) to the end of the past participle.
Utilizing the verb shodan (شدن), which means "to become," as you recall from Lesson 10. The third-person singular, whether present-tense or past-tense is used for the passive voice.
Examples of this include:
gofte shod (گفته شد) "It was said."
neveshte khāhad shod (نوشته خواهد شد) "It will be written."
sākhte mishavad (ساخته میشود) "The house is being built."
As you ought to know by now, there are substantial differences between spoken Persian and written Persian. In spoken Persian, the verb shodan (شدن) is entirely omitted, and the infinitive of the verb in question is used instead. The sentence ketab neveshte shod (کتاب نوشته شد), which means "the book was written," in spoken Persian would be ketab-ro neveshtan (کتاب رو نوشتن). (Note that the ro (رو) is the spoken Persian way of the object market rā (را), which will we cover in a letter lesson on prepositions.