The Passive Voice

Passive Voice

The passive voice is used when focusing on the person or thing affected by an action.

·The Passive is formed: Passive Subject To Be Past Particple

·It is often used in business and in other areas where the object of the action is more important than those who perform the action. For Example: We have produced over 20 different models in the past two years. Changes to: Over 20 different models have been produced in the past two years.

·If the agent (the performer of the action) is important, use "by" For Example: Tim Wilson wrote "The Flight to Brunnswick" in 1987. Changes to:"The Flight to Brunnswick" was written in 1987 by Tim Wilson.

·Only verbs that take an object can be used in the passive.

The following chart includes sentences changed from the active to the passive in the principal tenses.

 

Active	Passive	Time Reference
They make Fords in Cologne.	Fords are made in Cologne.	Present Simple
Susan is cooking dinner.	Dinner is being cooked by Susan	Present Continuous
James Joyce wrote "Dubliners".	"Dubliners" was written by James Joyces.	Past Simple
They were painting the house when I arrived.	The house was being painted when I arrived.	Past Continuous
They have produced over 20 models in the past two years.	Over 20 models have been produced in the past two years.	Present Perfect

 

An exercise to practice with the passive voice can be found in this link

 

Source: About.com http://esl.about.com/library/grammar/blpassive.htm