Passive voice: The woodcutter felled the trees
Columbs discovered America
The master praised the boy
The police arrested the thief
The boys were making kites
He has written a novel

The trees were felled by the woodcutter.
America was discovered by Columbus.
The boy was praised by the master.
The thief was arrested by the police.
Kites were being made by the boys.
A novel has been written by him.