IELTS Writing Task 1: Passive Voice for Process Diagrams

In IELTS Writing Task 1, you will usually be asked to describe data, like a bar chart or a line graph. But occasionally, the examiner will throw a curveball: a Process Diagram.

Instead of numbers and trends, you are presented with a flowchart showing how something is made (like brick manufacturing) or a natural cycle (like the life cycle of a frog).

If you try to write a process essay using standard, everyday grammar, your score will stall at a Band 5.5. Why? Because you are writing a story, not an objective report. To achieve a Band 7.0 or higher in Grammatical Range, you must completely overhaul your sentence structure and use the Passive Voice.

This guide breaks down exactly what the passive voice is, how to build it flawlessly, and the specific formulas you need to describe any manufacturing process like a true professional.

The Core Concept: Why Use the Passive Voice?

In everyday English, we use the Active Voice. The focus is on who is doing the action.

Active: “A worker mixes the ingredients.”

However, in an academic or industrial report, the person doing the work does not matter. The focus must be on the action itself and the object receiving the action. This is the Passive Voice.

Passive: “The ingredients are mixed.”

By removing the “worker” from the sentence, your writing instantly sounds more objective, formal, and academic—exactly what the IELTS examiner is looking for.

The Band 7.0+ Grammar Formula

Transforming a sentence from active to passive is like following a strict project blueprint. You just need to apply this three-step formula:

The Formula: Target Object + Verb 'To Be' + Past Participle (Verb 3)

Let’s look at how this applies to a real-world example, such as describing a bakery’s production line for mass-producing pineapple cream cakes.

Standard Active (Band 5.0)	The Passive Transformation (Band 7.0+)
First, a baker mixes the flour and sugar.	First, the flour and sugar are mixed.
Then, a machine injects the pineapple cream.	Then, the pineapple cream is injected into the center.
After that, a worker bakes the cakes at 180°C.	After that, the cakes are baked at 180°C.
Finally, they package the cakes into boxes.	Finally, the finished cakes are packaged into boxes.

Notice how the passive voice completely removes the “baker,” “machine,” and “worker”? The focus remains entirely on the cakes and the process.

Tense Selection: When to use which Passive?

A major mistake candidates make is using complex past or future tenses when describing a standard process. Keep your timeline tight and accurate.

The Present Simple Passive (The Default)

If the diagram shows a standard manufacturing process or a regular cycle, 90% of your essay should be in the Present Simple Passive.

Structure: am / is / are + Verb 3
Example: “The sorted materials are transported to the recycling facility.”

The Present Perfect Passive (The Sequence Linker)

To boost your grammatical range, use the Present Perfect Passive to show that one step is completely finished before the next step begins. This is an incredible tool for Coherence and Cohesion.

Structure: has been / have been + Verb 3
Example: “Once the raw materials have been sorted, they are immediately transported to the furnace.”

The Exception to the Rule: Natural Processes

There is one massive trap in the Task 1 Process diagram.

If you are given a manufacturing process (made by humans), you must use the passive voice. But if you are given a natural process (like the water cycle or the life cycle of a butterfly), you must generally use the Active Voice.

Why? Because nobody is “doing” the action to the subject; the subject is doing it naturally.

Manufacturing (Passive): “The coffee beans are dried in the sun.” (Someone put them there).
Natural (Active): “The water evaporates from the ocean.” (The water does this by itself; it is not ‘evaporated’ by someone).

Top 3 Exam-Day Execution Strategies

Drop the Agent: You do not need to say “by the machine” or “by the worker” at the end of every sentence. Only include the agent if it is absolutely critical to understanding the process (e.g., “The boxes are then loaded onto a truck by a forklift.”)
Master Your Signposting: A process is a sequence. You must guide the examiner from step to step using clear transition vocabulary. Use words like Firstly, Subsequently, Following this, At this stage, and Finally at the start of your passive sentences.
Combine Your Sentences: Earning a Band 8.0 requires complex sentences. Do not just write a list of short passive statements. Combine them using sequencing words like before and after.
- Band 6.0: “The tea leaves are picked. Then they are dried.”
- Band 8.0: “After being picked, the tea leaves are laid out in the sun to dry.”