In this Slides describes waht is Active & passive voice.

2. Ahsan Raza

3.  Active voice
If subject and object function remaining at their
proper place without disturbing the order of the
sentence, sentence is said to be active voice.
 Example
He writes a letter.
How did he solve the sums?

4.  Passive voice
If subject and object change their proper place
inverting the order of the sentence, the sentence is
called passive voice.
 Example
A letter is written by him.
How were the sums solved by him?

5.  Active & passive according to the tenses.
 Present indefinite tense:
Subject + is/am/are + 3rd form of verb + by + object.
Subject and object change place.
 Example
Active: He loves his son.
Passive: His son loved by him.
Active: They play hockey.
Passive: Hockey is played by them.

6.  Past indefinite tense:
Subject + was/were + 3rd form of verb + by + object.
Subject and object change place.
 Example
Active: She bought a book.
Passive: A book was bought by her.
Active: Ali took the thief to the station.
Passive: The thief was taken to the station by Ali.

7.  Future indefinite tense:
Subject + will be/shall be + 3rd form of verb + by +
object.
Subject and object change place.
 Example
Active: He will sell a house.
Passive: A house will be sold by him.
Active: I shall invite him.
Passive: He will be invited by me.

8.  Present continuous tense:
Subject + is/am/are + being + 3rd form of verb + by +
object.
Subject and object change place.
 Example
Active: We are doing our duty.
Passive: Our duty is being done by us.
Active: You are cheating me.
Passive: I am being cheated by you.

9.  Past continuous tense:
Subject + was/were + being + 3rd form of verb + by +
object.
Subject and object change place.
 Example
Active: He was playing football.
Passive: Football was being played by him.
Active: The teacher was teaching us a new lesson.
Passive: We were being taught a new lesson by the
teacher.

10.  Future continuous tense:
Subject + will be/shall be + being + 3rd form of verb +
by + object.
Subject and object change place.
 Example
Active: He will be taking tea.
Passive: Tea will be being taken by him.
Active: You will be telling a lie.
Passive: A lie will be being told by you.

11.  Present perfect tense:
Subject + has/have + been + 3rd form of verb + by +
object.
Subject and object change place.
 Example
Active: I have written a letter.
Passive: A letter has been written by me.
Active: He has eaten rice.
Passive: Rice has been eaten by him.

12.  Past perfect tense:
Subject + had + been + 3rd form of verb + by + object.
Subject and object change place.
 Example
Active: Mother had made food.
Passive: Food had been made by mother.
Active: We had not done over works.
Passive: Over works had not been done by us.

13.  Future perfect tense:
Subject + will/shall + have + been + 3rd form of verb +
by + object.
Subject and object change place.
 Example
Active: I shall have bought apples.
Passive: Apples will have been bought by me.
Active: You will have taken tea.
Passive: Tea will have been taken by you.