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.