The passive voice shifts focus from the person performing an action to the action itself or its result. In academic writing, this is one of the most important tools you have. When you write 'Scientists discovered a new species,' the emphasis falls on the scientists. But when you write 'A new species was discovered,' the emphasis shifts to the discovery — and that is usually what matters in reports, essays, and process descriptions.

Forming the passive is straightforward: you need a form of 'be' followed by the past participle of the main verb. The tense is carried entirely by 'be':

Present simple: The data is analysed regularly.
Past simple: The data was analysed last year.
Present perfect: The data has been analysed recently.
Future: The data will be analysed next month.
Present continuous: The data is being analysed now.

So when should you choose passive over active? There are three key situations:

1. The agent (doer) is unknown: 'The window was broken during the storm.' (We don't know who broke it.)
2. The agent is obvious or unimportant: 'The suspect was arrested.' (By police — this is understood.)
3. You want to keep the focus on the process or result: 'The vaccine was developed in record time.' (The achievement matters more than who achieved it.)

A common mistake is adding 'by + agent' to every passive sentence. In academic writing, only include the agent when it adds genuinely new or important information. 'The essay was written in three hours' is perfectly clear — you do not need 'by the student.'

Understanding when to use — and when to avoid — the passive is essential for IELTS and PTE. Examiners assessing Grammatical Range and Accuracy look for evidence that you can vary your sentence structures. Appropriate use of passive across different tenses demonstrates exactly that skill.

Process descriptions are one of the most common task types in IELTS Academic Writing Task 1, and they appear frequently in PTE Describe Image responses as well. Whether you are describing how chocolate is manufactured, how water is treated before it reaches your tap, or how a university application is processed, the passive voice is your primary tool. This is because in process descriptions, the focus is always on what happens at each stage — not on who performs the action.

When describing a general process (one that happens regularly or always), use the present simple passive:
'The raw materials are transported to the factory, where they are sorted by type.'

When describing a completed or historical process, use the past simple passive:
The building was designed in 2010 and was completed three years later.'

Getting this tense choice right is crucial. If you describe a factory production line that operates every day, the present tense is correct. If you describe how a particular building was constructed, the past tense is correct. Mixing these tenses within one description — without a clear reason — is a common error that examiners notice.

To connect the stages of a process, use a range of temporal markers rather than repeating 'and then' every time:

Sequencing: First, Initially, To begin with → Then, Next, Subsequently → Finally, Eventually
Temporal subordination: Once / After + present perfect passive, + present simple passive
'Once the beans have been roasted, they are ground into a fine powder.'
'After the samples had been collected, they were transported to the laboratory.'

This combination of passive voice and temporal subordination creates the kind of sophisticated process description that earns Band 7 or above in IELTS Task 1. A Band 5 or 6 writer typically uses active voice ('Someone collects the plastic') and simple connectives ('and then'). Moving beyond that pattern is what separates competent writers from strong ones.

In academic writing — particularly in IELTS Task 2 essays — you often need to present claims, opinions, and evidence without sounding too personal or too certain. The impersonal passive construction is one of the most effective ways to achieve this. Instead of writing 'Many people believe that education reduces poverty,' you can write 'It is widely believed that education reduces poverty.' The second version sounds more authoritative, more measured, and more appropriate for an academic context.

There are two main patterns for impersonal passive constructions:

Pattern 1: It is + past participle + that + clause
'It is argued that climate change poses the greatest threat to future generations.'
'It has been suggested that early intervention improves educational outcomes.'
'It is generally accepted that regular exercise benefits mental health.'

Common past participles used in this pattern include: argued, believed, considered, estimated, expected, hoped, known, proposed, reported, said, suggested, thought, widely accepted, generally acknowledged, broadly recognised.

Pattern 2: Subject + is said/believed/thought + to + verb
'The policy is believed to have reduced unemployment.'
'The new technology is expected to transform the industry.'
'The author is thought to have written the manuscript in 1847.'

These structures are particularly useful when you want to present a widely held view without attributing it to a specific source. They also serve as a form of hedging — acknowledging that a claim is a matter of debate rather than established fact.

However, be careful not to overuse them. If every sentence in your essay uses an impersonal passive, the writing becomes repetitive and hides your own argument. The best approach is to mix passive constructions with active voice: use passive for reporting general views and evidence, and active voice for presenting your own analysis and conclusions.

When should you NOT use passive? When you want to express your own position clearly. Statements like 'This essay argues that...' or 'The evidence strongly suggests that...' are more effective than hiding behind impersonal constructions when you need to take a clear stance.