Below 10 easy examples of voice change from active to passive are given. Notice how the subject, object, tense, pronoun and verb of the tense change.

Active VoicePassive Voice
Grandpa planted rose tree in our garden.Rose tree in our garden was planted by grandpa.
Newton discovered gravity.Gravity was discovered by Newton.
She was making a clay doll.A clay doll was being made by her.
Rajat builds houses.Houses are built by Rajat.
Wordsworth wrote wonderful poetries.Wonderful poetries were written by Wordsworth.
He had watched a movie.A movie had been watched by him.
Soma will write an essay.An essay will be written by Soma.
I have planted two trees.Two trees have been planted by me.
Satyajit Ray made Bengali films famous all over the world.Bengali films were made famous all over the world by Satyajit Ray.
The thief stole valuable items.Valuable items were stolen by the thief.