Passive voice - Extra

The examples

Tense

 

Subject

Verbs

(prepositional) Object

Present Continuous Active: Rita is writing a letter
  Passive: A letter is being written by Rita
Past Continuous Active: Rita was writing a letter
  Passive: A letter was being written by Rita
Past Perfect Active: Rita had written a letter
  Passive: A letter had been written by Rita
Future Perfect Active: Rita will have written a letter
  Passive: A letter will have been written by Rita