How do we make a passive sentence?

To learn how to make the passive we have to be familiar with the following sentence structure:

John	sends	Mary	a letter	every day.
Subject	Transitive verb	Indirect object:	Direct object:	time clause

               

To make passive sentences or phrase we need to follow these steps:

1. The subject becomes the agent. It is placed at the end of the sentence and takes the preposition “by”, and can be mentioned or not.
2. The Object (direct or indirect) becomes the passive subject.
3. The verb is changed into the passive.
4. Other sentence structures remain the same (eg. Time or frequency phrases) and are placed between the passive verb and the agent.

 Here is an example:

Active:

John	sends	Mary	a letter	every day
Subject	active verb	indirect object	direct object	time clause

Passive:

a letter	is sent	to Mary	by John	Every day.
Passive subject	passive verb	indirect object	agent	time clause

                                                

                                 

GENERAL RULE:

To make the passive of any verb we use the following structure:

verb “be” in the same tense as the active verb

+

past participle of the main verb

Example:

Am eating	=	Is being	+	eaten
present continuous of “eat”		present continuous of “be”		past participle of “eat”

THE FORM OF THE VERB “TO BE” AGREES WITH THE SUBJECT OF THE PASSIVE SENTENCE

Now watch the following video "Basic explanation of how the passive voice works":  

source: http://www.youtube.com/watch?v=BTGRYTuAjbA

If yoy want you can also have a look at the following websites for aditional information and exercises:

Active and passive voice (video)

General grammar (explanations and exercises)

special cases: verbs with two objects (explanations and exercises).