IELTS Writing Task 1 Process Diagram: Complete Guide & Sample Answer
IELTS Academic. Minimum 150 words. 20 minutes. One of six possible Task 1 visual types.
What is a Process Diagram question?
In a Process Diagram question, you are shown a sequence of stages. This is usually either a natural cycle, such as the water cycle or the life cycle of a frog, or a man-made manufacturing process, such as how coffee, paper, or bricks are made. You are then asked to describe how the process works from start to finish.
Unlike line graphs or bar charts, there is no data to compare. Instead, you are explaining a sequence of steps in the correct order.
This is one of the less common Task 1 visuals. As a result, many candidates feel unprepared for it. However, the structure is actually more predictable than charts, once you know the rules.
The Two Types of Process Diagrams
Process diagrams in IELTS Academic Writing Task 1 generally fall into two categories. The grammar you use depends entirely on which type you're given.
1. Man-made / manufacturing processes (e.g. how glass, paper, or instant coffee is made)
- Use present simple passive throughout: is/are + past participle
- Example: "The beans are picked, dried, and roasted."
- Passive voice is correct here because the process happens to the raw material. There's no need to mention who performs the action.
2. Natural processes / life cycles (e.g. the water cycle, a butterfly's life cycle, the rock cycle)
- Use present simple active voice
- Example: "The caterpillar hatches from the egg and feeds on leaves."
- Active voice is correct here because the subject, whether it's an animal, water, or rock, performs the action itself. Nothing is being "done to" it by an external agent.
Mixing these up is one of the most common errors examiners see. Using passive voice for a natural cycle, or active voice for a manufacturing process, directly affects your Grammatical Range and Accuracy score.
How to Structure Your Response
Like all Task 1 answers, a process diagram report follows a four-part structure. Aim for 12–16 sentences in total.
Introduction (1–2 sentences)
Paraphrase the question. State what the diagram shows and whether it is a natural cycle or a man-made process.
Overview (2–3 sentences)
Identify the starting point and ending point of the process, and state the total number of stages. Do not describe individual steps here. Save that detail for the body paragraphs.
Body Paragraph 1 (4–6 sentences)
Describe the first half of the process in chronological order. Use sequencing language to connect each stage clearly.
Body Paragraph 2 (4–6 sentences)
Describe the second half of the process through to completion. Maintain the same chronological flow and grammatical voice established in Body 1.
Sample Question and Model Answer
The diagram below shows the process by which instant coffee is produced. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.
The diagram shows an 11-stage process: picking coffee beans, drying, roasting, cooling, grinding, mixing with hot water, straining, freezing, re-grinding, vacuum drying, and packaging into jars.
Model Answer (Band 7+)
The diagram illustrates the stages involved in manufacturing instant coffee, from the initial harvesting of coffee beans through to the final packaged product.
Overall, the process consists of eleven distinct stages and is fundamentally linear. It begins with the picking of raw coffee beans and ends with the packaging of coffee granules for distribution to shops. Notably, several stages, such as drying and grinding, occur more than once during the process.
The process begins with coffee beans being picked from the fields. These beans are then dried, roasted, and left to cool. After that, they are passed through a grinding machine, which transforms them into fine coffee granules. Once ground, the coffee passes to the sixth stage, where it is mixed with hot water to create a liquid solution. This mixture is then strained to remove any solid particles.
Following the straining stage, the liquid is frozen. It is then passed through the grinder for a second time, breaking the frozen mixture into smaller pieces. This frozen substance is next placed in a vacuum, where it is dried so that the water content evaporates. As a result, only the coffee granules remain. Finally, these granules are packaged into jars, ready to be transported to retail outlets for sale.
Examiner Commentary
Task Achievement: All eleven stages are accounted for and described in the correct sequence. The overview correctly identifies the start and end points and the total number of stages without going into unnecessary detail.
Coherence and Cohesion: Clear paragraph breaks separate the first half of the process from the second half. In addition, sequencing language such as "following the straining stage," "once ground," and "finally" guides the reader through the process logically.
Lexical Resource: Process-specific vocabulary is used accurately: "harvesting," "transforms," "solution," "evaporates." Repetition of "is/are + past participle" is varied with phrases like "passed through" and "left to cool" to avoid monotony.
Grammatical Range and Accuracy: Present simple passive is used consistently and correctly throughout, which is appropriate for a man-made manufacturing process. Relative clauses, such as "which transforms them into," and time clauses, such as "once ground," add grammatical variety.
Essential Vocabulary for Process Diagrams
Sequencing language
first · initially · subsequently · following this · once this stage is complete · after that · the next stage involves · finally · at the final stage
Describing manufacturing processes (passive voice)
is extracted · is processed · is transferred to · is converted into · is treated with · is packaged · is transported · is distributed
Describing natural processes (active voice)
emerges from · develops into · evolves into · matures into · is released · evaporates · condenses · circulates
Useful linking phrases
this is followed by · at this point · once this has occurred · simultaneously · meanwhile · in the final stage
Common Mistakes to Avoid
- Using the wrong voice. Using active voice for a manufacturing process, or passive voice for a natural cycle, is a frequent and costly error. Therefore, always check which type of process you're describing before you start writing.
- Missing the overview. As with all Task 1 answers, omitting the overview paragraph caps your Task Achievement score. This happens regardless of how well you describe the individual stages.
- Listing without sequencing language. Simply stating "Stage 1... Stage 2... Stage 3..." without connecting words makes your answer read like a list. As a result, your Coherence and Cohesion score will suffer.
- Switching tenses unnecessarily. Process diagrams should stay in the present simple tense throughout. Never switch to past or future, even though the process is multi-step.
- Forgetting the number of stages. Stating the total number of steps in your overview, for example "the process consists of X stages," is a simple, high-value detail that examiners specifically look for.
Frequently Asked Questions
Should I use passive or active voice for a process diagram?
It depends on the type of process. Use passive voice for man-made or manufacturing processes, since the material is acted upon. Use active voice for natural processes or life cycles, since the subject acts on its own.
How many paragraphs should my process diagram answer have?
Four in total: an introduction, an overview, and two body paragraphs that split the process roughly in half chronologically.
Do I need to mention every single stage shown in the diagram?
Yes. Task Achievement is partly assessed on whether you've covered all key stages. However, you can group very minor or closely related steps together in one sentence if needed to stay within a reasonable word count.
Can a process diagram have more than one diagram, like a "before and after" comparison?
Occasionally, yes. IELTS sometimes includes two process diagrams to compare, such as an old factory process versus a modernized one. In that case, you would need an additional comparative paragraph highlighting the key differences between the two processes.