How to Describe Any Process Diagram in IELTS Task 1

A process diagram has no numbers in it. That is why candidates who are comfortable with bar charts and line graphs freeze when one appears. There is nothing to compare, no highest value, no trend, and none of the language you practised for figures is useful.

The good news is that process diagrams are the most predictable Task 1 question there is. Every one of them, whether it shows cement production, glass recycling, silk farming or the life cycle of an insect, answers the same four questions. Once you can answer those four, the writing is mechanical.

This post gives you the method and a full sample answer you can copy the shape of.

The four questions, in order

Spend three minutes on these before writing a word.

1. How many stages are there? Count the arrows or boxes. The number goes in your overview.
2. What goes in and what comes out? The first input and the final product. These also go in your overview.
3. Is it linear or a cycle? A linear process ends with a product. A cycle returns to its starting point, so the final sentence connects back to the first stage.
4. Is it natural or man made? This decides your grammar, which the next section explains.

Answer those and you already have your overview, which is the single highest value sentence in a Task 1 response. Task Achievement, the first criterion, explicitly rewards a clear overview of the main features, and a process diagram without one is capped low no matter how good the detail is.

Passive or active: the one grammar decision

This is where marks are quietly lost.

Man made processes take the passive. Someone performs each step, but who they are is unknown and unimportant, so the agent disappears. The clay is mixed with water. The mixture is then heated to 1400 degrees. Writing workers mix the clay invents information the diagram does not give you.

Natural processes take the active. Nature is the agent and it is visible. Water evaporates from the ocean. The larvae hatch and feed on leaves. Forcing a passive here produces strange English: the water is evaporated suggests something evaporated it.

If a diagram mixes both, mix both. A recycling process usually has natural drying and man made crushing in the same picture.

Sequencing without repeating yourself

You need roughly eight to ten stage markers across the answer, and then eight times is a Lexical Resource problem. Rotate through these:

1. Beginning. At the first stage, To begin with, The process starts when
2. Middle. Once this is complete, After the mixture has cooled, At the next stage, The material then passes to
3. Simultaneous. At the same time, While this is happening
4. End. Finally, In the last stage, At this point the cycle begins again

Two of these are worth learning properly because they show grammatical range: Once the pulp has been dried, it is pressed into sheets and Having been sorted by colour, the glass is crushed. Each one packs two stages into one sentence, which is exactly what Grammatical Range and Accuracy is looking for.

A full sample answer

The diagram below shows how glass bottles are recycled.

Sample response, 178 words.

The diagram illustrates the stages involved in recycling used glass bottles into new glass containers.

Overall, the process is a cycle rather than a linear sequence, consisting of seven main stages that begin with the collection of used bottles from consumers and end with new bottles being returned to shops for sale. The process is entirely man made and requires two periods of heating.

At the first stage, empty bottles are placed by consumers in special collection points, from which they are transported by lorry to a recycling plant. On arrival they are washed thoroughly in hot water to remove any remaining liquid and labels.

Once the bottles have been cleaned, they are sorted by colour into clear, green and brown glass. Each colour is then crushed by machine into small fragments known as cullet.

In the next stage, the cullet is fed into a furnace, where it is melted at approximately 1500 degrees Celsius. The molten glass is subsequently poured into moulds to form new bottles, which are cooled and finally delivered to supermarkets, at which point the cycle begins again.

Look at what that answer does. Sentence one paraphrases the question. Paragraph two is the overview, and it contains the stage count, the input, the output, and the fact that it is a cycle. The three body paragraphs group the seven stages into three logical blocks rather than listing them one by one, which is what earns Coherence and Cohesion above band 6.

The mistakes that cap the score

1. No overview. The most expensive omission in Task 1. Two sentences, always in the same place, always covering stage count and start to finish.
2. Inventing numbers or reasons. If the diagram does not say why the glass is sorted by colour, do not explain it. Task 1 reports; it does not analyse.
3. One sentence per stage. Seven stages become seven identical short sentences, which reads as a list and limits your grammar range.
4. Writing under 150 words. The minimum is a rule, and falling below it costs marks directly. Our guide on the 150 word minimum explains how the penalty works.
5. Copying the question wording. Paraphrase it. The diagram shows how glass bottles are recycled becomes the stages involved in recycling used glass bottles.

Practise it in ten minutes

Find any process diagram, set a timer for three minutes, and write only these four lines: the stage count, the input, the output, and linear or cycle. Then write the overview paragraph from those four lines and stop. Do that five times with five different diagrams and the overview will take you ninety seconds in the real test, which is where the time for the detail paragraphs comes from.

For a worked example of a natural process, where the active voice applies throughout, see our water cycle diagram answer.

When you write a full response, Bandly will give you estimated band scores for all four Task 1 criteria and point at the sentences behind each one. The estimates are produced by a language model rather than a qualified examiner, so treat them as feedback on your draft rather than a forecast of your test result.