IELTS Academic Task 1 process diagrams: how to describe each stage

A process diagram has no numbers to compare, so the job is different from a chart. You describe the stages in order, from the first to the last, and you show the examiner that you can see how the process is organised. Count the stages, find where the process splits into two phases, and describe each phase in its own paragraph, mostly with passive verbs.

For the rules that apply to every Task 1 visual, see our Academic Writing Task 1 guide.

What does a process question look like?

As of November 2026, IELTS describes Academic Writing Task 1 as presenting "one or more graphs, charts or tables" or "a diagram of an object, device, process or event". You should spend no more than 20 minutes on it and write at least 150 words. Task 2 counts twice as much as Task 1, so Task 1 is one third of your Writing score.

Process diagrams come in two kinds:

• Man-made processes have a clear start and end: raw material goes in, a product comes out.
• Natural processes are often cycles with no real start or finish, such as the water cycle.

For both, the main features you must select and report are the stages and their order.

How to read the diagram before you write

Spend two or three minutes on the diagram. Write short notes next to it.

1. Count the stages. Number them on the question paper if the diagram doesn't. The number goes in your overview.
2. Find the start and the end. What goes in, and what comes out? In a cycle, start where the arrows seem to begin.
3. Look for a natural break. Most processes divide into two phases, such as preparation and production. That break is where your first body paragraph ends.
4. Read every label. Labels give you vocabulary, plus times or temperatures that belong in your answer.
5. Check for branches. If a product goes two ways (packaged, or sent back for reuse), mention both.

How do you write an overview with no numbers?

The public band descriptors say a band 7 Task 1 answer "presents a clear overview of main trends, differences or stages". For a process, "stages" is the word that applies. A clear overview usually says three things in one or two sentences:

• how many stages there are,
• where the process begins and where it ends,
• one feature of its shape, such as two main phases, or a cycle that repeats.

The better version gives the examiner the structure of the whole process before any detail.

The grammar: passive voice and sequencing

Present simple passive

Most man-made processes are described in the passive, because the focus is on what happens to the material, not on who does it.

• The olives are washed in cold water.
• The paste is spread onto mats.
• The oil is stored in steel tanks for two months.

The form is am/is/are + past participle. The two most common errors are leaving out is/are ("the olives washed") and using the wrong participle ("the paste is spreaded"). Check irregular verbs before the test: ground, spun, kept, frozen, cut, put.

Natural processes usually take the active voice, because nobody is doing anything: the water evaporates, the larva grows.

Sequencing without repetition

"Then" repeated six times makes an answer read like a list. Vary the way you link stages:

Clause linking is where many band 6 answers lose out. Compare:

The olives are washed. Then they are crushed. Then the paste is mixed.

Once the olives have been washed, they are crushed into a paste, which is then mixed slowly for about 30 minutes.

The second version joins three stages with a time clause and a relative clause. That shows grammatical range and reads as one connected process.

A sample answer

The task (original): The diagram below shows the stages in the production of olive oil. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

The diagram (described here in words) shows eight stages: (1) olives harvested from trees using nets and shakers; (2) olives taken by truck to the mill within 24 hours; (3) leaves removed by a blower and olives washed in cold water; (4) olives crushed into a paste by steel rollers; (5) paste mixed slowly for 30–40 minutes (malaxation); (6) paste spun in a centrifuge, separating oil from water and solids; (7) oil stored in stainless steel tanks for two months; (8) oil filtered and bottled. A side arrow at stage 6 shows the solids sent away to be used as fuel or fertiliser.

The diagram illustrates how olive oil is made, from the harvest to the bottling of the finished product.

Overall, the process consists of eight stages and can be divided into two phases. In the first, the olives are harvested and prepared, and in the second, oil is extracted from them, stored and bottled. One by-product, the solid waste, is reused rather than thrown away.

To begin with, the olives are harvested from the trees with nets and mechanical shakers. They are then taken by truck to a mill, and this must happen within 24 hours of picking. At the mill, a blower removes any leaves, after which the fruit is washed in cold water. Once the olives are clean, they are crushed into a paste by steel rollers.

In the second phase, the paste is mixed slowly for 30 to 40 minutes before being spun in a centrifuge. This separates the oil from the water and solids, and the solids are sent away to be used as fuel or fertiliser. The oil itself is kept in stainless steel tanks for two months. Finally, it is filtered and poured into bottles, ready for sale.

That is 192 words.

Comments, using the four criteria:

• Task Achievement. The overview gives the number of stages, the two phases and the by-product. All eight stages are covered, including the branch at stage 6, and nothing is invented.
• Coherence and Cohesion. The paragraph break matches the break in the process. Linking varies: to begin with, then, after which, once, before being, finally. "This separates..." uses this to refer back to the previous stage.
• Lexical Resource. Label words are reused where needed (centrifuge, by-product) and paraphrased elsewhere: picking for harvest, mixed slowly for malaxation.
• Grammatical Range and Accuracy. Passive forms are accurate throughout, mixed with active verbs where they fit (a blower removes). There are time clauses, a relative clause and a participle phrase (before being spun).

Common mistakes

Skipping stages. If the diagram has nine stages and you describe seven, the examiner notices. Tick each number on the question paper as you write it.

Explaining the science. "The olives are crushed because the oil is inside the cells of the fruit" adds information that is not in the diagram. Describe, don't explain.

Copying the labels as a list. Labels are in note form ("leaves removed"). Turn them into full sentences: the leaves are removed by a blower.

Wrong voice for natural cycles. Passive suits factories. Active suits nature. Mixing them up is one of the most frequent grammar errors we see in practice tests.

Going short. Diagrams with few labels tempt people to stop at 120 words. Under 150 is a problem. If you're short, check that every stage has its own clause and that the branch and end product are described.

Forgetting the overview. Without an overview, Task Achievement is unlikely to go above 5. This is as true for diagrams as for graphs.

Practice: plan two diagrams

Use these two original stage lists to practise planning. Write the overview and one body paragraph for each.

Task A: how a household rainwater tank system works. (1) rain falls on the roof; (2) water flows into gutters; (3) a leaf screen removes leaves and twigs; (4) a first-flush diverter sends the first, dirtiest water to the ground; (5) water is stored in a tank; (6) a pump sends water to the toilet and washing machine; (7) when the tank is full, extra water leaves through an overflow pipe to the garden.

Task B: how fabric is made from recycled plastic bottles. (1) bottles are collected from homes; (2) they are sorted by colour at a recycling plant; (3) labels and caps are removed; (4) bottles are cut into small flakes; (5) flakes are washed and dried; (6) flakes are melted and pushed through fine holes to make thread; (7) thread is wound onto reels; (8) thread is woven into fabric for bags and jackets.

Checklist for each plan:

• [ ] I counted the stages and the number is in my overview.
• [ ] I said where the process starts and ends.
• [ ] I found the break between two phases (A: collecting and using; B: preparing and making).
• [ ] I mentioned the branch in Task A (the overflow and the first-flush water).
• [ ] I used the passive for every stage done by a machine or person.
• [ ] I joined at least two pairs of stages in one sentence with once, after or which.

When you're ready to try one under time pressure, the free Writing section of our practice test includes a Task 1 question with an estimated score on the four criteria. For Task 2 essays, our free essay checker gives a score and corrections in about 30 seconds. If you're also working on graphs, our line graph guide covers trend language.