In English, verbs are either active or passive in voice.

In the passive, the object of an active verb becomes the subject of the passive verb, and the subject becomes the object of the “by-phrase”.

(Intransitive verbs and linking verbs are always in the active voice.)

                   S          V                O

Active:      Bob    mailed    the package.

                  S                  V               “by-phrase”

Passive:  The package was mailed by Bob.

Form of the passive: be + past participle

 

1. Simple Tenses: 

Simple present: I write a letter =  The letter is written.

Simple past:  I wrote a letter.   =  The letter was written.

Simple future: I will write a letter  =  The letter will be written.

Sometimes a “by-phrase” is not used when it’s is not known or not important to know who performs an action.

That sweater was made in Korea. (by someone)

 

2. Progressive Tenses:

Present Progressive:  I’m writing a letter. = The letter is being written

Past Progressive: I was writing a letter. = The letter was being written.

 

3. Perfect Tenses 

Present Perfect: I have written a letter.  = The letter has been written. 

Past Perfect:     I had written a letter.   =    The letter had been written. 

Future Perfect: I will have written a letter. = The letter will have been written. 

 

4. Modals

Have to: I have to write a letter. = The letter has to be written. 

Must: I must write a letter. = The letter must be written. 

Should: I should write a letter. = The letter should be written.

Can: I can write a letter. = The letter can be written.