In English, the subject of a sentence is usually an actor that is doing an action. For example: The boy broke the window.
In this sentence, the boy is the actor who did the action (breaking). The object of the sentence (the window) is what receives the action. The sentence is about the subject (the boy), which is more important than the object of the verb (the window). This is an active sentence, which is also called the active voice.
The Passive Voice: "The window was broken by the boy."
In a passive sentence, the situation is the opposite. We move the object of the verb (window) to the beginning of the sentence, so it can become the subject. This is how we build a passive sentence:
Subject (The window) + BE verb (was) + past participle (broken) [+ by actor (by the boy)]*
* the phrase by the boy is optional.
Why do we use the passive voice? There are several reasons. Here are four of them.
Reason #1: The object of the verb is more important.
Which is more important: the police (the subject) or the body (the object)? Answer: The body! That is the surprising information! And because the object of the sentence is the most important thing, we change the sentence to the passive voice. We move the object of the verb to the beginning of the sentence so it can become the subject: A body was found in the park (by the police). In this sentence, you probably don't even need to say "by the police" because that information isn't important. The most important thing is the body so it becomes the subject and the first word of a passive sentence.
Reason #2: We don't know who the actor is.
In the above active sentence, the subject ("someone") doesn't give us any useful information. We don't know who killed John F. Kennedy so there isn't really a reason to make "someone" the subject. Again, like reason #1, the object of the verb (John F. Kennedy) is the most important thing.
Reason #3: The actor is obvious so you don't need to say it.
Does the active sentence give us any useful information? No. Why? Well, when we see the verb speak, we know that we are talking about people. People are the only animals who would be able to speak a language like English. There can be no other subject. So, in this case, we can make a passive sentence to focus on the object (English).
Reason #4: You don't want to say who the actor is.
Are you John's friend? If so, you might want to use the passive sentence. The passive sentence doesn't focus on the actor. In fact, it doesn't even mention John. By using the passive voice, we can take the attention away from the actor and just focus on the object that received the action (the report). The report wasn't finished on time. By not including the actor, the listener doesn't know who to blame.
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A good example of why we use the passive voice can be seen in this simple conversation:
A: When were you born?
B: I was born in 1978.
Did you know that both the question and the answer are in the passive voice? The word 'born' is the past participle of the verb bear (bear/bore/born). We don't ask "Where did your mother bear you?" nor do we answer "My mother bore me in 1978" because we want to talk about you, not your mother. Your mother is not important (Rule #1). In addition, we don't use the active voice because we know that your mother bore you. The only person that can give birth to a person is his or her mother. The actor is obvious so we don't need to say it (Rule #3)
Note: You can only use the passive voice with transitive verbs. Transitive verbs, such as eat, throw, and read, are followed by a direct object. You can eat something, throw something, and read something. Intransitive verbs, such as happen, come, and die, are not followed by a direct object. You cannot happen something, you cannot come something, you cannot die something. Because intransitive verbs do not have a direct object, they cannot be used in the passive voice.
I hope this is helpful. I have included some exercises below if you want to practice.
- Matthew Barton / Creator of Englishcurrent.com
Passive Voice Practice Exercises
Passive Voice Exercise #1
Change the active sentences to the passive voice. (Only present simple and past simple tenses)
1. I didn't fix the problem.
2. Police protect the town.
3. John's mother raised him in a small town.
4. Someone painted the building last year.
5. Alexander Fleming discovered penicillin in 1928.
6. Nowadays, some students study grammar on the Internet.
Passive Voice Exercise #2
Complete the sentences using one of the verbs in the below box. Change the verbs to the correct tense (present or past).
- Many accidents by dangerous driving.
- Cheese from milk.
- The roof of the building in a storm a few days ago.
- You to the wedding. Why didn't you go?
- A cinema is a place where films .
- In the United States, elections for president every 4 years.
- Originally, the book in Spanish, and a few years ago it into English.
- Passive Voice Exercises
- Identifying Passive or Active Sentences in Newspaper Headlines
- Ergative Verbs & Passive Voice