Passive voice is a specific form of the verb that we use to take an active subject out of the sentence. It is important that the action happens but it is not important who exactly does this action.
Active: We are building a house.
Passive: The house is being built. It doesn't matter who is building it.
Active: I'm sending the email.
Passive: The email has been sent. It doesn't matter who has sent it.
If we want to mention who does the action or what caused it, we can use "by".
The house was built by a leading development company. A leading development company built the house.
The email has been written by the technical support. The technical support wrote the email.
Severe damage was caused by the storm. The storm caused severe damage.
How to make passive
It is very simple to build the passive voice in any English tense. We always make passive by using to be + past participle, where the past participle never changes and "be" indicates a tense.
Passive = be done, where "be" changes according to the tense
To make passive in a certain English tense, we put the verb "be" into the form that it takes in this tense.
Passive and the most common tenses
|You are employed.
||The script is being written.
||The changes have been made.
||I was born on the third of March, 1987.
||The room was being cleaned when we entered.
||The house had been renovated before it was sold.
||The task will be completed tomorrow.
We make question sentences in the passive voice in the same way as in all the tenses. The auxiliary verb can be composed of one, two or even three words. But no matter how many words there are, the first word goes before the subject and all others go after the subject.
Examples of questions
Are you paid well? (Present simple)
Have the changes been made? (Present perfect)
Why was the room being cleaned? (Past continuous)
When will the task be completed? (Future simple)
How long has the script been being written? (Present perfect continuous)
Passive with modal verbs
We can use passive voice with other verbs including the modals:
modal verb + be + past participle
modal verb + have been + past participle
Examples of active and passive voice with modals
You must finish the work within two hours. → The work must be finished within two hours.
No one must see me. → I mustn't be seen.
We should cancel the meeting. → The meeting should be cancelled.
I can hear the sound. → The sound can be heard.
We might have predicted the changes. → The changes might have been predicted.
I could have sold my car for five thousand pounds. → My car could have been sold for five thousand pounds.
"To" + passive infinitive
There are a lot of words after which we can put "to + infinitive" (e.g. eager to do something, need to do something). We can use an active or a passive voice after "to". The infinitive of the passive is "be":
to be + past participle
Every child wants to be praised.
My cat doesn't like to be petted.
An employee has the right to be paid.