What is the Passive Voice?
In general, sentences are active. They contain a subject (the thing that does the action), a main verb and an object (the thing that receives the action). The sentence looks like this:
Subject + main verb + object
The boy kicked the dog.
In an active sentence, the subject comes before the main verb and the object comes after.
Sometimes, we are more interested in the recipient of the action and the action itself. We don’t want or need to know who does the action. We express this as a passive sentence:
The dog was kicked.
Subject + main verb
In this case, the original object (the dog) has changed position and now comes before the main verb because it has become the subject of the sentence (there is now no object as such).
When a sentence has no object and the verb uses to be + past participle, this is what is known as the Passive Voice.
Why do we use it?
It is only used when we want to focus on the receiver of the action rather than the doer of the action.
This might be because it is obvious who does the action, therefore you do not need to explicitly state it, eg.
The man was fired from his job (by his boss).
Or it could be because you do not know who did the action, eg.
Bob’s bike was stolen (by someone).
Or because it’s not important who did the action, eg.
The library will be closed at 5pm (by the manager).
The Passive Voice is quite formal so it is commonly used in academic or scientific writing, to make it sound less personal and less subjective, eg.
Several observations were noted during the experiment.
Will I need to use the Passive Voice in the IELTS exam?
It is possible you will come across the Passive Voice in any of the papers in the IELTS exam, but you will only need to use it yourself in possibly the Speaking exam or the Writing exam.
In the Speaking exam, it is up to you how you want to use it, if at all. The most common reasons you might need it are when referring to a person who was born in a certain time/place, a book which was written by a certain author, or a film which was produced by a certain director. You will probably already be familiar with these phrases and not even be consciously aware that you are using this particular grammatical structure.
You might also want to use it in Writing Task 2 when expressing commonly held beliefs or attitudes, eg. It is often thought that… or It is believed that…
However, if you are doing the Academic module rather than the General Training module, it is important that you familiarise yourself with how to use the Passive voice in case you get a Process diagram for your Writing Task 1. When describing a process, in general we are not interested in who does the action, we are interested in the activity itself. The actions are the focus of the sentence and become the subject, using the Passive Voice. It would sound strange to have a description of a process that was written completely in the Active Voice because this would not be natural and doing so could negatively impact your score in three of the four marking criteria: Task Achievement, Coherence and Cohesion, and Grammatical Range and Accuracy.
Look at the diagram below which shows the process for making and distributing cement.
Read the first partial description below, written in the Active Voice.
People make cement using two raw materials called gypsum and clinker. After the machines have produced it, machines transfer it to a large storage tank. From there, machines package the cement in one of three ways, according to the volume needed by the end consumer. The mode of transport will depend on the size of the packaging. Tankers transport cement in bulk volumes whereas either ships or lorries dispatch bagged cement, according to the size of the bags.
Now compare that paragraph with the one below, written in the Passive Voice.
Cement is made using two raw materials called gypsum and clinker. After it has been produced, the mixture is then transferred to a large storage tank. From there, the cement is packaged in one of three ways, according to the volume required by the end consumer; bulk, jumbo or 50kg bags. These are then ready for distribution to the purchaser or consumer. The mode of transport will depend on the size of the packaging. Cement in bulk volumes is sent by tanker, whereas bagged cement is dispatched by ship or lorry, according to the size of the bags.
Which reads better? Why?
Now read the second paragraph again and underline all the examples of the Passive Voice.
For a more in-depth look at the grammar of the Passive Tense, check out this link here from IELTS Buddy.