To use the passive voice in English:
1) locate the subject and object of the active statement:
John translates a lot of documents.
John – subject
a lot of documents – object
2) change the active verb into the passive form according to this pattern:
be (in the right tense) + past participle of the main verb
John translates a lot of documents.
A lot of documents are translated by John.
The following transformations from the active to the passive are necessary in these tenses:
Present Simple passive: am/are/is + past participle
Computers are turned off at the end of each day.
Past Simple passive: was/were + past participle
Computers were turned off yesterday.
Present Continuous passive: am/are/is being + past participle
Computers are being turned off right now for security reasons.
Past Continuous passive: was/were being + past participle
Computers were being turned off for security reasons.