The passive form of the sentence 'I have killed the bird.' is -

• Present Perfect Tense এর Active voice কে passive করতে হলেঃ

- Active voice এর object কে subject করতে হবে (subjective form) + have/has + been +
verb এর past participle + by + subject এর objective form.

Example:
Act: He has eaten rice.
pass: Rice has been eaten by him.

উপরের নিয়মানুযায়ী সঠিক উত্তর হবেঃ The bird has been killed by me.

Source: A paassage to the English Language by S.M.Zakir Hussain.