Active and Passive voice

This video is an introduction to active and passive voice. In this video we will look at how to form the passive, and then we will consider why we would use it in our academic writing.

‘The passive’—or ‘the passive voice’—is not a tense. The term ‘voice’ describes the relationship between the verb, the subject, and the object of a sentence. We use the active or passive voice to emphasise different parts of a sentence. New learners of English generally learn the active voice first. Here is an example sentence in the active voice.

The teacher showed a film about deep and surface approaches to learning.

This sentence, like many in the active voice in English, has the following structure:

SUBJECT plus VERB plus OBJECT.

This subject, verb, object order—or SVO—is the most common structure in English so you are probably very familiar with it.

The passive voice is formed by changing the order of the active sentence so that the object of the active sentence becomes the subject of the new sentence. Meanwhile, the subject of the active sentence becomes known as the ‘agent’ and the passive sentence would be:

A film about deep and surface approaches to learning was shown (by the teacher).

Notice that the verb “showed” has now been changed to “was shown”. Both these are in the past tense because, when forming the passive voice, we don’t change the tense.  We use the ‘be’ verb in the same tense as the original sentence and add the past participle of the main verb.

Notice also that the form of the verb ‘be’ must maintain subject-verb agreement with the new subject, as in this example:

A film was shown by the teacher.

but

Two films were shown by the teacher.

For more on this, refer to the video on subject-verb agreement.

Sometimes a clause or sentence has multiple objects: one direct and the others indirect. For example:

The researchers gave specific information to the participants.

In this sentence, specific information is the direct object of the verb ‘gave’ and the participants are the indirect object.

The writer can choose which of these objects will become the subject in the passive voice, depending on what they want to emphasise. For example:

Specific information was given to the participants (by the researchers).  

or

The participants were given specific information (by the researchers).

Did you notice how the form of the verb “be” changed in each sentence to agree with the subject?

Now that we know what the passive voice looks like, we need to consider when and why we would choose to use the passive voice instead of the active.

First, it is better to use the passive voice when we want readers to focus on the result of an action rather than the person or thing that is doing it. For example, we might say:

A free trade agreement between Australia and Indonesia has been announced by the foreign minister.

rather than:

The foreign minister has announced a free trade agreement between Australia and Indonesia.

because we are more interested in the free trade agreement than the foreign minister.

We would also use the passive voice if the agent of the sentence is obvious, or not relevant or repetitive within the text. For example, we would say:

Glass is classified as a solid.

rather than:

Scientists classify glass as a solid.

Lastly, the passive voice is preferred if we want to avoid naming the agent of an action.  For example, we would say:

Women, because of their biological function as child bearers, were traditionally confined to the home.

rather than:

Men traditionally confined women to the home because of the female’s biological function as child bearers.

The passive voice is quite common in academic writing, especially when writing about experiments and processes, where the agent is usually not stated. For example we might say:

The mixture is heated to 300 degrees.

Of course, the writer always needs to use the correct tense within a passive sentence, as within active sentences. Can you name the tenses in the examples on the screen? You can pause the video if you need more time.

Here is an example of another process, this time related to law.

The man was arrested, then he was detained in a cell for three hours before being released.

Notice the different tenses being used in the passive form.

In academic writing, the passive is also frequently used to introduce ideas using the word ‘it’, for example:

It is often suggested that….

It is argued that...

It has been argued that….

It has been said that…

You will probably hear different opinions about the use of the active and passive voice in academic contexts. Preferences and trends can vary from discipline to discipline and often from person to person. Certain types of text use the passive more often than others. Pay attention to whether it is common in the textbooks, journal articles, and other academic sources written by expert writers in your discipline. Also remember this guiding principle: make sure your choice of active or passive voice is intentional and deliberate. That means you know why you are using it to emphasise information and make your meaning clear to the reader.

In this video we have looked at how to form the passive voice and why we might use it instead of the active voice. Now try the exercises below to practise what you’ve learned.

Diseth, Å., & Martinsen, Ø. L. (2003). Approaches to learning, cognitive style, and motives as predictors of academic achievement. Educational Psychology, 23(2), 195-207.