When students prepare for IELTS Academic Writing Task 1, process charts can initially seem quite confusing. Unlike graphs and charts that mainly require comparisons and numerical analysis, a process diagram asks you to explain how something is made, produced, prepared, or transformed from one stage to another.
One of the most important grammar features you need to understand when describing a process is passive voice. This is what we teach you at Tiju’s Academy, the best IELTS coaching centre in Kerala. Many students make the same mistake: they see an action in the diagram and immediately try to identify a person who performs that action. However, in most IELTS process diagrams, the person or group responsible for an action is either not shown or is not important.
That is exactly where passive voice becomes useful. For example, imagine that a diagram shows a mixture being heated. The diagram tells us what happens to the mixture, but it does not tell us who heats it.
A common mistake would be:
Workers heat the mixture.
Why is this unsuitable?
Because the diagram does not mention workers. You have introduced information that is not provided in the visual.
A better sentence would be:
The mixture is heated.
Here, the attention remains on the process rather than on an imaginary person.
So, let us understand exactly why passive voice is commonly used in IELTS Writing Task 1 Process Charts, how to form it, when to use it, and how it can improve the quality of your answer.
What Is a Process Chart in IELTS?
A process chart presents a sequence of stages showing how something happens.
It could describe:
- The production of a product
- The manufacturing of a material
- A natural process
- The recycling of waste
- The preparation of food
- The treatment of water
- The creation of a particular substance
- The life cycle of an organism
Your job is to report the information shown in the diagram clearly and logically. You are not expected to invent information. This is one of the most important principles to remember.
If the diagram does not tell you who performs an action, you should not create a person, worker, company, machine operator, or organisation yourself.
Instead, describe the action using passive voice.
Why Is Passive Voice So Important?
The main reason is simple: the process is more important than the person performing the action.
Consider this example:
The water is filtered.
The important information is that the water goes through a filtration stage.
We do not necessarily need to know who filters it.
Compare that with:
Workers filter the water.
This sentence changes the focus. Now, the emphasis is on the workers.
But if the process diagram does not show workers, mentioning them is unnecessary and potentially inaccurate. Therefore, passive voice allows you to describe exactly what the diagram presents without adding unsupported information.
Active Voice vs Passive Voice
Before using passive voice confidently, you need to understand the difference between active and passive sentences.
Active Voice
In active voice, the subject performs the action.
Subject + Verb + Object
Example:
Workers heat the mixture.
Here, workers are the subject, heat is the verb, and mixture is the object. The sentence focuses on the workers.
Passive Voice
In passive voice, the object of the active sentence becomes the focus.
Object + be + past participle
Example:
The mixture is heated.
Here, the mixture becomes the subject of the sentence.
The person performing the action is either unknown, obvious, or unimportant. This makes passive voice particularly suitable for many process descriptions.
A Simple Example
Imagine a process diagram showing these stages:
Raw material is collected.
It is transported to a factory.
The material is cleaned.
It is heated.
The final product is packaged.
Notice something important.
The diagram focuses on the material and what happens to it. It may not identify individual people at every stage.
Therefore, we can write:
The raw material is collected and transported to the factory. It is then cleaned before being heated. Finally, the finished product is packaged.
This sounds natural because the emphasis remains on the sequence of events.
Common Passive Voice Examples for Process Charts
The mixture is heated.
Instead of:
Workers heat the mixture.
The water is filtered.
Instead of:
Workers filter the water.
The final product is packaged.
Instead of:
Employees package the final product.
The materials are transported to the factory.
Instead of:
Drivers transport the materials to the factory.
Unless drivers are specifically shown or mentioned, there is no need to introduce them.
The bottles are cleaned before being filled.
This allows you to explain multiple stages smoothly without repeatedly mentioning imaginary people.
When Should You Use Passive Voice?
Passive voice is particularly useful when the doer of an action is not shown.
Ask yourself one simple question:
Does the diagram tell me who performs this action?
If the answer is no, passive voice is often the safest and most appropriate choice.
For example:
The beans are roasted.
You don’t need to say:
Workers roast the beans.
unless the diagram actually identifies workers.
Similarly:
The liquid is transferred into a container.
is better than:
A worker transfers the liquid into a container. if no worker appears in the diagram.
Don’t Add Information That Isn’t in the Diagram
This is one of the biggest lessons for IELTS Process Chart questions. Your task is to report the information provided, not to create a story around it.
Suppose the diagram shows:
Milk to Heated to Cooled to Stored
You should not write:
Factory employees heat the milk before a technician cools it.
Why?
Because the diagram hasn’t told you that employees or technicians are involved.
Instead, write:
The milk is heated before being cooled and stored.
This is concise, accurate, and focused on the information provided.
Why Does Passive Voice Sound Natural in Process Descriptions?
Think about how instructions and manufacturing processes are normally described.
We often say:
The ingredients are mixed.
The mixture is heated.
The liquid is filtered.
The material is dried.
The bottles are labelled.
The products are transported.
These sentences naturally focus on the stages of the process.
That is exactly what you need to do in IELTS Task 1.
You are essentially answering:
What happens at each stage?
rather than:
Who does every action?
How to Form Passive Voice?
The basic structure is:
Subject + form of be + past participle
For example, present simple passive:
The mixture is heated.
The materials are transported.
The bottles are cleaned.
The form of be changes depending on whether the subject is singular or plural.
Singular:
The product is packaged.
Plural:
The products are packaged.
The main verb appears in its past participle form.
For example:
heat becomes heated
filter becomes filtered
package becomes packaged clean becomes cleaned transport becomes transported mix becomes mixed produce becomes produced
For irregular verbs, the form changes differently:
make becomes
made
build becomes built
send becomes sent
grow becomes grown
Passive Voice for Different Process Stages
A process answer usually contains several stages, so you need a range of useful passive structures.
Collection:
The raw materials are collected.
Transportation:
The materials are transported to the factory.
Cleaning:
They are then cleaned.
Mixing:
The ingredients are mixed together.
Heating:
The mixture is heated.
Filtering:
The liquid is filtered.
Cooling:
The substance is allowed to cool.
Packaging:
The finished product is packaged.
Distribution:
Finally, the products are distributed to retailers.
Learning these structures can make process questions much easier.
Passive Voice Helps You Avoid Repetition
Another advantage of passive voice is that it can make your writing more concise.
Imagine repeatedly writing:
Workers collect the material. Workers transport the material. Workers clean the material. Workers heat the material.
This becomes repetitive and unnatural.
Instead:
The material is collected and transported to the factory, where it is cleaned and subsequently heated.
This version sounds much more appropriate for an academic process description.
Passive Voice and IELTS Grammar
Grammar is one of the four areas assessed in IELTS Writing.
A strong Task 1 response should demonstrate an appropriate range of grammatical structures.
Using passive voice correctly can help you show that you can adapt your grammar to the type of information you are describing.
However, remember:
Don’t use passive voice simply to make your answer look complicated.
The goal is accuracy and natural usage.
If an active sentence is clearly appropriate because the person performing the action is actually shown in the diagram, you can use active voice.
For example, if a diagram explicitly shows:
A technician checks the equipment.
Then:
A technician checks the equipment. may be completely appropriate.
The key is to follow the information in the diagram.
A Very Important Rule for Students
Here is an easy rule you can remember during the IELTS exam:
If the doer is not shown, don’t invent the doer.
Instead, focus on the object receiving the action.
For example:
Doer not shown:
The water is filtered.
Doer not shown:
The mixture is heated.
Doer not shown:
The product is packaged.
This simple strategy can help you avoid unnecessary information.
How to Connect Passive Sentences?
A good IELTS process answer should not sound like a list of disconnected sentences.
Use sequencing and linking expressions to create a smooth description.
Useful expressions include:
Initially
First
At the first stage
Next
Subsequently
Following this
After that
Once this is completed
In the next stage
Finally
At the final stage
For example:
Initially, the raw materials are collected and transported to a processing facility. Once they arrive, they are cleaned and sorted according to their type. Subsequently, the materials are heated before being cooled. Following this stage, the resulting substance is filtered. Finally, the finished product is packaged and prepared for distribution.
A Model Process Paragraph
Initially, the raw materials are collected and transported to a processing facility. Once they arrive, they are cleaned and sorted according to their type. The selected materials are then mixed together before being heated at a high temperature. Following this stage, the resulting substance is cooled and filtered. Finally, the finished product is packaged and prepared for distribution.
This paragraph works well because it follows the sequence, focuses on the process, avoids inventing people, uses passive structures naturally, uses appropriate linking expressions, and clearly explains the stages.
Mistakes Students Should Avoid
Mistake 1: Inventing workers
Workers heat the mixture.
If workers aren’t shown, don’t introduce them.
The mixture is heated.
Mistake 2: Using only active voice
Some students believe active voice is always better.
That is not true.
Process diagrams often require passive constructions because the focus is on what happens to the materials or products.
Mistake 3: Making every sentence passive
The opposite extreme is also a problem.
You don’t need to force passive voice into every sentence.
Use active voice when it naturally describes the information.
Mistake 4: Forgetting the past participle
Incorrect:
The mixture is heat.
Correct:
The mixture is heated.
Incorrect:
The water is filter.
Correct:
The water is filtered.
Mistake 5: Forgetting subject-verb agreement
Incorrect:
The materials is transported.
Correct:
The materials are transported.
Incorrect:
The product are packaged.
Correct:
The product is packaged.
A Quick Exam-Time Strategy
When you receive a Process Chart in the IELTS exam, follow these steps.
Step 1: Identify the stages.
Look carefully at the beginning, middle, and final stages.
Step 2: Identify the main subject.
Ask yourself:
What is being changed, moved, produced, cleaned, heated, or transformed?
Step 3: Check whether the doer is shown.
If the person performing the action is not mentioned, don’t invent one.
Step 4: Choose passive voice where appropriate.
For example:
The liquid is filtered.
Step 5: Connect the stages.
Use words such as:
Initially, next, subsequently, finally.
Step 6: Check your grammar.
Look especially for is and are, past participles, subject-verb agreement, articles, and prepositions.
The Golden Rule to Remember
If you remember only one thing from this lesson, remember this:
Focus on WHAT HAPPENS, not WHO DOES IT.
If a diagram shows a mixture being heated but doesn’t show who heats it, don’t create a worker.
Write:
The mixture is heated.
If the diagram shows water going through filtration, write:
The water is filtered.
If it shows the final product being prepared for sale, write:
The product is packaged.
Your responsibility in IELTS Writing Task 1 is to describe the information that is actually presented.
You don’t need to create imaginary workers, technicians, factory employees, engineers, or companies.
Conclusion
Passive voice is commonly used in IELTS Writing Task 1 Process Charts because these diagrams frequently focus on the stages and transformations involved in a process rather than the people responsible for carrying them out.
When the person performing an action is unknown, unimportant, or simply not shown, passive voice allows you to describe the process accurately without adding information that isn’t provided.
So, instead of thinking:
Who is doing this?
Train yourself to think:
What is happening here?
That small change in thinking can make process chart writing much easier.
Remember these three examples:
The mixture is heated.
The water is filtered.
The product is packaged.
If no person is shown in the diagram, don’t invent one.
Stay focused on the process, follow the sequence carefully, use passive voice where appropriate, and make sure every sentence is supported by the information given in the chart.
With regular practice, and a guide like Tiju’s Academy, the best IELTS coaching centre in Kerala will help you with process charts and it can become one of the most manageable parts of IELTS Writing Task 1.
For more IELTS Writing tips, grammar strategies, and practical exam guidance, check out the our blogs and follow TIJU’S Academy, the best IELTS institute in Kerala for more useful IELTS content.
Frequently Asked Questions:
A: Because process diagrams focus on the stages of a process, not on the people doing the actions. In most diagrams, the person responsible is either not shown or not important, so passive voice lets you describe exactly what the diagram presents without adding extra information.
A: A process chart shows a sequence of stages explaining how something happens. It could show how a product is made, how a material is manufactured, a natural process, waste recycling, food preparation, water treatment, the creation of a substance, or the life cycle of an organism.
A: Only if the diagram actually shows workers. If it doesn't, you are adding information that isn't in the visual. Write "The mixture is heated" instead, so the focus stays on the process.
A: In active voice, the subject performs the action (Subject + Verb + Object), for example, "Workers heat the mixture." In passive voice, the thing receiving the action becomes the subject (object + be + past participle), for example, "The mixture is heated."
A: Use the subject, a form of "be," and the past participle of the verb. For example: "The mixture is heated." "The materials are transported," "The bottles are cleaned."
A: Use "is" with a singular subject and "are" with a plural subject. For example: "The product is packaged" and "The products are packaged."
A: Common ones include make → made, build → built, send → sent, and grow → grown. Regular verbs simply take "-ed," such as heated, filtered, packaged, cleaned, transported, mixed, and produced.
A: Ask yourself: "Does the diagram tell me who performs this action?" If the answer is no, passive voice is usually the safest and most appropriate choice.
A: No. Don't force passive voice into every sentence. Use active voice when it naturally fits, for example, if the diagram clearly shows "A technician checks the equipment."
A: Not always. Many students believe active voice is always better, but process diagrams often need passive structures because the focus is on what happens to the materials or products.
A: Grammar is one of the four areas assessed in IELTS Writing, and using passive voice correctly shows you can adapt your grammar to the information you are describing. However, the goal is accuracy and natural usage, not making your answer look complicated.
A: Instead of repeating "Workers collect the material. Workers transport the material. Workers clean the material," you can write: "The material is collected and transported to the factory, where it is cleaned and subsequently heated." It is shorter and sounds more academic.
A: Useful expressions include "initially," "first," "at the first stage," "next," "subsequently," "following this," "after that," "once this is completed," "in the next stage," "finally," and "at the final stage."
A: "Initially, the raw materials are collected and transported to a processing facility. Once they arrive, they are cleaned and sorted according to their type. The selected materials are then mixed together before being heated at a high temperature. Following this stage, the resulting substance is cooled and filtered. Finally, the finished product is packaged and prepared for distribution."
A: The main mistakes are inventing workers who aren't shown, using only active voice, making every sentence passive, forgetting the past participle (writing "The mixture is heat" instead of "heated"), and wrong subject-verb agreement (writing "The materials is transported" instead of "are").
