In short: Describe a process by sequencing its stages in order using the present simple passive (the clay is shaped). Write an introduction, an overview stating the number of stages and whether the process is linear or cyclical (no figures), then describe each stage in order with varied sequencing connectors.
A process diagram in IELTS Academic Writing Task 1 asks you to describe how something is made or how something works — the stages of a manufacturing process, a natural cycle, or a life cycle. Unlike a bar chart or line graph, there are almost no figures to report. The examiner is testing whether you can sequence the stages clearly and use the passive voice accurately. This guide gives you a reliable method and the exact language you need.
What the examiner wants
The four Task 1 marking criteria reward a particular skill on a process diagram:
- Task Achievement — an overview that states how many stages there are and whether the process is linear (start to finish) or cyclical (it loops back), plus an accurate, complete description of each stage in order.
- Coherence & Cohesion — sequencing language that moves the reader from one stage to the next without listing "and then… and then…".
- Lexical Resource — the vocabulary of the topic (e.g. raw materials, fermentation, recycling) and a range of sequencing connectors.
- Grammatical Range — the present simple passive for most processes (the beans are dried), because the focus is on the action, not who does it.
A reliable method
- Identify the start and the end. Find the first input and the final output — this anchors the whole description.
- Count the stages and decide the shape. Is it linear (raw material → finished product) or cyclical (it returns to the start)? This goes in your overview.
- Number the stages in order before you write anything, so you don't miss one or describe them out of sequence.
- Write the introduction by paraphrasing the prompt — don't copy it.
- Write a one- or two-sentence overview stating the number of stages and the overall shape, with no detail.
- Write the body in order, one stage flowing into the next, using sequencing connectors and the passive.
The language that scores
Sequencing connectors (vary them — don't repeat "then"):
- Beginning: to begin with, initially, in the first stage, the process begins when…
- Middle: next, after that, subsequently, once X has been completed, at this point
- Showing purpose/result: so that, in order to, which causes, resulting in
- End: finally, in the final stage, the process is complete when…
The passive voice (the backbone of process writing):
The harvested beans are washed and then are left to dry in the sun. Once dry, they are transported to a factory, where they are roasted at a high temperature.
Cyclical signals, if the process loops:
- the cycle then repeats, this stage returns the water to the ocean, the process begins again
A worked sample answer
Prompt: The diagram below shows how bricks are manufactured for the building industry.
The diagram illustrates the stages involved in manufacturing bricks for the construction industry, from the extraction of clay to delivery.
Overall, the process is linear and consists of seven main stages, beginning with the digging of raw clay and ending with the finished bricks being packaged and delivered.
To begin with, clay is dug from the ground using a digger. It is then passed through a metal grid onto a roller, which breaks it down, before sand and water are added to produce a smooth, even mixture.
In the next stage, the clay is shaped into bricks, either by a mould or by a wire cutter. The bricks are then dried in a drying oven for one to two days. Subsequently, they are heated in a kiln at a moderate and then a high temperature, after which they are left to cool in a cooling chamber for two to three days. Finally, the finished bricks are packaged and delivered to their destination.
This answer states the number of stages and the linear shape in the overview, then describes every stage in order, using the present simple passive throughout.
Common mistakes to avoid
- Using the active voice everywhere. "A worker digs the clay" is weaker than "the clay is dug" — the process, not the worker, is the focus.
- No overview, or an overview that dives into detail. The overview = number of stages + linear or cyclical.
- Missing or reordering a stage. Number them first.
- Repeating "then". Rotate your sequencing connectors.
- Wrong tense. Processes are general truths — use the present simple, not the past, unless the diagram shows a historical process.
Frequently asked questions
Do process diagrams need an overview? Yes — state how many stages there are and whether the process is linear or cyclical. That is the overview; keep detail out of it.
What tense and voice should I use for a process? The present simple passive (is heated, are dried), because the focus is the action rather than who performs it.
How do I avoid repeating "then"? Rotate your sequencing connectors: initially, next, after that, subsequently, once X is complete, and finally.
Are there any numbers to report in a process? Usually none — processes are about stages and sequence, not figures.
Practise this
You now have the method. The fastest way to make it automatic is to write under guidance and get feedback on your sequencing and passive structures. Work through the free IELTS Writing Task 1 lessons — every lesson is hand-built by a teacher, and you get instant examiner-aligned feedback on what you write.