A Transitive Verb has two voices - The Active Voice and The Passive Voice.
Here the person or thing denoted by the Subject is said to do something.
Rama kills a snake.
Here the person denoted by the Subject, namely, Rama, does something to a snake.
Here the person or thing is said to suffer something from some other person or thing.
A snake is killed by Rama.
Here the thing denoted by the Subject, namely, a snake, suffers something from Rama.
An Intransitive Verb is not used in the Passive Voice, unless it takes a Cognate Object in the Active.
1. He ran a great risk. (Active)
2. A great risk was run by him. (Passive)
3. I eat an apple. (Active)
4. An apple is eaten by me. (Passive)
5. He killed a lion. (Active)
6. A lion was killed by him. (Passive)
7. They wrote the will. (Active)
8. The will was written by them. (Passive)
9. It gave birth to a baby-elephant. (Active)
10. A baby-elephant was given birth by it. (Passive)
When a sentence is changed from the Active form to the Passive, the Object to the Active Verb becomes the Subject to the Passive Verb.
Object to Active Verb
1. Animals cannot make tools.
2. Animals do not possess hands.
3. The king punished the thief.
4. We drove him out of the house.
5. We need six camels for our work.
6. The shepherd has lost six sheep.
7. I have bought a new house.
8. God will bless good men.
9. Some boys were flying kites.
10. Who broke the window?
11. Have you shut the door?
12. Why did your sister give such a rude reply?
Subject to Passive Verb
1. Tools cannot be made by animals.
2. Hands are not possessed by animals.
3. The thief was punished by the king.
4. He was driven out of the house by us.
5. Six camels are needed by us for our work.
6. Six sheep have been lost by the shepherd.
7. A new house has been bought by me.
8. Good men will be blessed by God.
9. Kites were being flown by some boys.
10. By whom was the window broken?
11. Has the door been shut by you?
12. Why was such a rude reply given by your sister?
The Agent of A Verb in the Passive Voice is not always stated either. Because it is understood from the rest of the sentence.
1. There was a loud explosion and all the windows were shattered.
Here we understand that all the windows were shattered by the explosion.
Because we can infer it.
1. The thief has been arrested.
We infer that the arrest was made by the police.
Because the agent is of no interest to us.
1. This wine has been diluted.
We are not interested in who diluted it, but merely in the fact of its having been diluted.