It is a gramatical construction where the noun or noun phrase that would be the object of an active sentence appears as the subject of a sentence with passive voice.

Example: He stole my book. à My book was stolen by him.

• Structure

Subject + finite form of to be + Past Participle

• Use of Passive

- When the actor is unknown.
-When the actor is irrelevant.
-When you want to vague about who is responsible.
-When you are talking about a general truth.

• Examples

Present:

-Cars are assembled in Japan.
-Cats are eaten by my dog.
-English class is given by Alba Marron.
-The militaries are attacked in Irak.
-The homework is done by me.

Past:

-The Eiffel tower was built by Gustave Eiffel.
-The Olympic games were won by USA in London.
-The swimming competition was won by Michael Phelps.
-Mexicali was founded in 1903.
-America was discovered by Columbus in 1492

Future:

-A new house will be bought by my mom.
-Mexico City will be visited by my family in December.
-iPods will be modified by Apple.
-Army will be prepared for WWIII.
-A new heels will be used by me next weekend.

Present perfect:

-The car has been driven by my grandmother.
-The cookies have been made by my sister in law.
-Internet has been developed by humans.
-GTA has been produced by Rockstar Games.
-The psychologist has been visited by Sarah.

 Karen H.