Active sentences in the present perfect tense have the following structure:
Subject + has/have + past participle form of the verb + object
Passive sentences in the present perfect tense have the following structure:
Object of the active sentence + has/have + been + past participle form of the verb + by + subject of the active sentence
Changing an assertive sentence into the passive
Active: I have written a story.
Passive: A story has been written by me.
Active: They have built a house.
Passive: A house has been built by them.
Active: He has broken my window.
Passive: My window has been broken by him.
Active: I have placed an order for a digital camera.
Passive: An order for a digital camera has been placed by me.
Active: She has done her work.
Passive: Her work has been done by her.
Changing a negative sentence into the passive
Active: I have not received a telegram.
Passive: A telegram has not been received by me.
Active: She has not written a story.
Passive: A story has not been written by her.
Active: She has not cheated anybody.
Passive: Nobody has been cheated by her.
Changing an interrogative sentence into the passive
Passive forms of these sentences will begin with has or have. When the active sentence begins with a question word (e.g. when, where, which, why etc.), the passive sentence will also begin with a question word. When the active sentence begins with who or whose the passive sentence will begin with by whom or by whose. When the active sentence begins with whom, the passive sentence will begin with who.
Active: Have you kept the secret?
Passive: Has the secret been kept by you?
Active: Who has done this?
Passive: By whom has this been done?
Active: Why have you told a lie?
Passive: Why has a lie been told by you?
Active: Who has torn my book?
Passive: By whom has my book been torn?
Active: Have you written the letter?
Passive: Has the letter been written by you?
Active: Has the policeman caught the thief?
Passive: Has the thief been caught by the policeman?
Active: Has the postal department released a new stamp?
Passive: Has a new stamp been released by the postal department?