Grammar: Passive structures

"Do you remember why and how we use the passive voice in English? Well, let's have a quick review of the basis," Professor Lovegood added vigorously.

Let's see. In English, we differentiate between active and passive voice.

In the active voice, the subject is the 'actor' that performs ac action. This is called the agent. For example:

Professor Malfoy drank two cups of tea.

In this sentence, Professor Malfoy (that is the actor) did an action (drank). The object (two cups of tea) receives the action. Thus, the sentence is about the subject, not the object of the verb.

On the other hand, in the passive voice, the situation is the opposite. We begin with the object, which is more important in this case, becoming the subject. For example:

Two cups of tea were drunk [by Professor Malfoy]

This is how we build a sentence using the passive voice:

Subject (Two cups of tea) + BE verb (were) + past participle (drunk) [+ by the agent (by Professor Malfoy)]*

*The agent is optional

Then, why do we use the passive voice?

#1: The object of the verb is more important.

Example: 

Active: The police found a body in the market.

Passive: A body was found [by the police] in the market.

Which one do you think is more important: the police (subject) or the body (object)? Well, the body, of course! Because of it, we change the sentence from active to passive.

#2: We don't know who the actor is.

Example:

Active: Someone murdered my neighbour two days ago.

Passive: My neighbour was murdered (by someone) two days ago.

In this sentence, the subject someone does not add any useful information to us. It is unknown who murdered my neighbour, so there is no need to use someone as the subject. You don't even have to include by someone in the sentence. As in #1, the object is the most important thing in the sentence.

#3: The actor is obvious, so you don't need to mention it.

Example:

Active: The painter painted the house last week.

Passive: The house was painted [by the painter] last week.

In this case, it is obvious that the painter (subject) is the one that did the action. However, it does not give us any useful information because, when we see the verb 'paint', we all know that it's talking about a painter. So, we can employ the passive to focus on the object instead of the subject.

#4: You don't want to say who the actor is.

Example: 

Active: John made mistakes.

Passive: Mistakes were made [by John].

Suppose that John is your friend. In order to be polite, you may use the passive voice so that the focus narrows to the object (mistakes) without even needing to mention John. By doing so, the attention is taken away from the actor and then, the hearer doesn't know who to blame.

Note that you can only use the passive structure with transitive verbs (such as eat, read, and paint). Transitive verbs are followed by a direct object. On the other hand, intransitive verbs (such as happen, come, and talk) are not followed by a direct object. You cannot talk something, but you can read something.

But, what if we want to use an intransitive verb in passive voice? To do this, we need an impersonal construction, which is called impersonal passive.

Example: He says > It is said

Impersonal passive isn't common in English and it is only possible with verbs of perception (such as think, say, and know).

Example: They say that children are afraid of ghosts > It is said that children are afraid of ghosts.

Now, how do we distinguish between passive and active voice?

• First, if there isn't BE + Past Participle in the sentence, it cannot be a passive sentence.

Mary was reading a book. (Not passive - no BE + Past Participle)

• Second, look at the subject and the verb of the sentence. Then, ask yourself: "is the subject an actor (did Mary read?) or is the subject the object of the verb (did someone read Mary?)? Consequently, if the subject is the actor, then it is an active sentence. If the subject is the object of the verb, then it's a passive sentence.

Let's have a look at some examples using different tenses:

What do you think? Easy, right? Now, what if we try with more difficult tenses? Here you go:

I think you all can manage it. But, what happens when we have two objects in the sentence? Well, when there are two objects in the active sentence, one becomes the subject, while the other one remains an object. In order to choose which one is transformed into a subject, it depends on what you want to focus on.

It's time to see if you have understood how the passive voice works. Here you have an exercise to put it in practise. Good luck!

References:

https://examples.yourdictionary.com/examples-of-active-and-passive-voice.html

https://www.englishcurrent.com/exercises/passive-voice-exercises/

https://www.englishcurrent.com/grammar/english-grammar-passive-voice/

https://www.ego4u.com/en/cram-up/grammar/passive