Why this one is different
Every other Task 1 chart gives you numbers changing over time. A process diagram gives you stages happening in order. That changes almost everything about what you write.
| A line graph or bar chart needs… | A process diagram needs… |
|---|---|
| Trend verbs (rose, fell, plateaued) | Nothing of the kind. There is no trend. |
| Figures and units | No figures at all. There is usually not a number on the page. |
| Comparisons between series | Sequence. What happens first, next, after that. |
| Active voice (sales increased) | The passive. The water is filtered. |
Candidates who have drilled trend language for weeks often freeze here, or worse, force it in — "the number of stages rose to seven" — which is not English about a process at all.
The passive voice, and why it is not optional
In a process, nobody is named. The diagram does not tell you who filters the water or who packs the bottles, and inventing an agent is a mistake. So English uses the agentless passive.
| Wrong (invents an actor) | Right (agentless passive) |
|---|---|
| Workers collect the raw material. | The raw material is collected. |
| They heat the mixture to 200°C. | The mixture is heated to 200°C. |
| The factory packs the product. | The product is packed and labelled. |
| Someone transports it to shops. | It is then transported to retailers. |
If the diagram is a natural cycle — a water cycle, a life cycle — the active voice is correct instead, because nature is the actor: the water evaporates, the larvae hatch. Use the passive for manufactured processes, the active for natural ones.
Sequencing: more than 'firstly, secondly'
You need to make the order unmistakable, but reaching for firstly / secondly / thirdly on every stage is the mechanical linking the band descriptors warn about. Vary it.
| Position | Language |
|---|---|
| Start | The process begins when… · At the first stage… · Initially, |
| Middle | Once this is complete,… · The … is then … · After being …, · At this point, |
| Simultaneous | Meanwhile, · At the same time, |
| Result | This results in… · The result is… · …, which produces… |
| End | Finally, · In the final stage, · …, at which point the process is complete. |
Two structures are worth using deliberately because they are complex and they carry sequence at the same time:
- Once / After + being + participle: After being washed, the beans are dried.
- Which clause for the result: The mixture is heated, which causes the water to evaporate.
The overview: count the stages
The overview is worth the same here as anywhere else — omitting it caps Task Achievement — but what goes in it is different. There is no trend to summarise, so instead:
- How many stages are there?
- What does it start with, and what does it end with?
- Is it linear or a cycle? A cycle has no end, and saying so is a real observation.
Weak (restates the title): "The diagram shows the process of making cement."
Strong (a real overview): "Overall, the process consists of six main stages, beginning with the extraction of raw materials and ending with the packaging of the finished cement. It is a linear process, and the material is transformed by heat at the halfway point."
That paragraph contains no detail from any single stage, and it demonstrates that you understood the diagram as a whole — which is exactly what the criterion is asking.
The structure
- Introduction (1 sentence). Paraphrase the title — do not copy it. Copied language earns nothing.
- Overview (2 sentences). Number of stages, start, end, linear or cyclical.
- Body 1. The first half of the stages, in order.
- Body 2. The remaining stages, through to the end.
At least 150 words, no conclusion, no opinion, and no speculation about why the process is done this way. It is a report.
The mistakes that cost the most
- Using the active voice with an invented actor. Workers put the bottles in boxes. The diagram never said there were workers.
- Forcing trend language in. There is no increase in a process diagram.
- Numbering every stage with firstly, secondly, thirdly, fourthly. Mechanical linking is a band 6 marker.
- Skipping the overview, which is the single most expensive omission in the whole task.
- Explaining or evaluating. This method is very efficient. Nothing in the diagram says so.
Frequently asked questions
Should I use the passive voice in an IELTS process diagram?
Yes, for manufactured processes — nobody is named in the diagram, so English uses the agentless passive: 'the mixture is heated', not 'they heat the mixture'. It is the natural register, so it scores on Task Achievement, and it is a complex structure, so it also scores on Grammatical Range. For natural cycles like the water cycle, use the active voice instead, because nature is the actor.
Can I use trend vocabulary like 'rose sharply' in a process diagram?
No — there is no trend and usually not a single figure on the page. A process shows stages happening in order, so what it needs is sequencing language and the passive voice. Forcing in trend vocabulary is one of the clearest signs a candidate has drilled line graphs and not read the task.
What goes in the overview of a process diagram?
Not a trend, because there isn't one. Say how many stages there are, what the process begins and ends with, and whether it is linear or a cycle. Omitting the overview caps your Task Achievement score, exactly as it does on any other Task 1 chart.
Should I explain why the process is done that way?
No. Task 1 is a report, not an argument. The diagram does not tell you why a stage exists or whether the method is efficient, so any explanation or evaluation is outside the task and earns nothing.