Task 1 – process diagrams

How to describe a manufacturing process or natural cycle in IELTS Writing Task 1, using the passive voice, sequencing language and a clear overview.

A process diagram shows how something is made or how something happens: the production of olive oil, the recycling of glass, the life cycle of a salmon, the water cycle. There are no numbers to compare and no trends. That worries many candidates, but a process is in fact the most predictable Task 1 of all, because the diagram gives you the content and the order. Your job is to turn pictures and labels into clear, connected sentences.

Two kinds of process

Structure

Divide the stages at a natural break: for example, preparing the raw material / turning it into the product; or what happens in the factory / what happens afterwards.

The overview for a process

Count the stages and identify the first and last.

Overall, the production of olive oil is a linear process consisting of seven main stages, beginning with the harvesting of the fruit and ending with the bottling and distribution of the finished oil.

For a cycle:

Overall, the life cycle of the salmon has three main phases, which take place in three different environments: the upper river, the lower river and the open sea, before the adult fish return to where they were born.

For a manufacturing process you can also mention the main kinds of activity: …the process involves both mechanical stages, such as crushing, and the use of heat.

The passive voice

In a manufacturing process, we are interested in what happens to the material, not in who does it. English uses the passive for this.

Present simple passive: is/are + past participle

Other passive forms that add range:

• After a modal: The paste must be stirred continuously. / The bottles can then be reused.
• Present perfect passive (for a completed earlier step): Once the olives have been washed, they are crushed.
• Passive -ing form: After being sorted, the glass is crushed. / Before being delivered…
• Reduced relative clause: The oil produced in this way is stored in steel tanks.

Learn the past participles of common process verbs:

collect – collected · sort – sorted · wash – washed · crush – crushed · grind – ground · mix – mixed · heat – heated · melt – melted · cool – cooled · dry – dried · press – pressed · filter – filtered · pour – poured · shape – shaped · cut – cut · pack – packed · store – stored · deliver – delivered · transport – transported · remove – removed · add – added · separate – separated · feed – fed · leave – left · take – taken · send – sent

Not every verb is passive. Things that happen by themselves stay active: the water evaporates, the mixture cools, the liquid flows into…, the fish grow.

Sequencing language

Avoid starting every sentence with Then. The most effective way to sound fluent is to join two stages in one sentence:

First, the olives are picked. Then they are washed. → After being picked, the olives are washed in cold water. The paste is pressed. Oil and water come out. → The paste is pressed, which releases a mixture of oil and water. The oil is filtered. Then it is bottled. → The oil is filtered before being bottled.

Using the labels

The diagram gives you nouns (crusher, storage tank, conveyor belt) and sometimes verbs. Use every label, but turn notes into grammar:

If you do not know a word for a piece of equipment, describe its function: a machine which separates the oil from the water.

Do not add steps or explanations that are not shown.

Worked example

Task: The diagram below shows how olive oil is produced.

Stages shown:

1. Harvesting – olives picked from trees (autumn)
2. Washing – cold water; leaves and stones removed
3. Crushing – ground into a paste by a mill
4. Stirring – paste mixed slowly, 30 minutes
5. Pressing – oil and water separated from solids
6. Separating – centrifuge removes water from oil
7. Storage and bottling – steel tanks; bottled; delivered to shops

Model answer (176 words)

The diagram illustrates the steps by which olives are turned into olive oil ready for sale.

Overall, this is a linear process consisting of seven main stages, beginning with the harvesting of the fruit and ending with the delivery of bottled oil to shops. Most of the stages are mechanical, and no heat is applied at any point.

The process begins in autumn, when ripe olives are picked from the trees. They are then washed in cold water, which removes any leaves and stones. Once they are clean, the olives are fed into a mill, where they are ground into a thick paste. This paste is stirred slowly for about thirty minutes.

In the next stage, the paste is pressed so that the liquid it contains, a mixture of oil and water, is separated from the solid matter. The liquid is subsequently spun in a centrifuge in order to remove the water. Finally, the pure oil is stored in steel tanks before being bottled and delivered to shops.

What to notice

• Passive verbs throughout: are picked, are washed, are fed, are ground, is stirred, is pressed, is separated, is spun, is stored.
• Varied linking: when, then, which removes, Once…, where…, In the next stage, so that, subsequently, in order to, Finally, before being…
• Purpose is expressed where the diagram shows it: so that the liquid… is separated, in order to remove the water.
• Every label has been used, and nothing has been invented.

Natural cycles

For a life cycle or a natural process, use the active voice and the present simple, and show that the end leads back to the beginning.

The cycle begins when the adult female lays her eggs in the gravel of a fast-flowing upland stream. After about five months, the eggs hatch into small fish known as ‘fry’, which remain in the upper river for up to four years. They then migrate downstream… Finally, the mature salmon return to the river in which they were born in order to breed, and the cycle starts again.

Useful verbs: lay (eggs), hatch, grow, develop into, feed on, migrate, mature, reproduce, evaporate, condense, fall as rain, flow, sink, rise.

Common mistakes

• No overview, because ‘there are no trends’. There must still be one: stages, start, end.
• Active voice with a vague subject: ✗ They wash the olives. People crush them.
• Wrong participle: ✗ are grinded → ✓ are ground; ✗ is dryed → ✓ is dried.
• Listing with ‘then… then… then’. Combine stages.
• Describing the drawing: ✗ In the picture there is a big machine. Describe the process.
• Adding your own knowledge about how the product is really made.

Key points

• Processes need an overview too: number of stages, beginning and end, linear or cyclical.
• Manufacturing → present simple passive; natural cycles → present simple active.
• Vary your sequencing and join stages with once, after which, before being, which then.
• Use all the labels and nothing else.

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