Band 6.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 6.5 · Cambridge IELTS 19 · 2026-08-17

IELTS Writing Task 1 question

 

The diagram below shows how a biofuel called ethanol is produced.

Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

Student answer (Band 6.5)

The diagram displays a cyclical process of ethanol production which is a biofuel.

Overall, the biofuel production system has multiple stages. It includes both natural and industrial steps, starting with planting trees and harvesting them to fermentation using microbes to turn it into ethanol. This is then used as a fuel in various transports that releases carbon dioxide back into the environment, restarting the whole process.

First of all, trees are planted and grown using natural energy from sunlight and carbon dioxide in the atmosphere. When trees are matured, they are harvested and cut into pieces to generate cellulose. The next stage is performed in industrial facilities.

In the following stages, the cellulose is processed into sugars. Here the sugars are broken down into pieces using microbes through fermentation and finally ethanol is created, a key stage in the whole process. The ethanol is then used as fuel for a different range of vehicles such as cars, trucks and airplanes. When the ethanol is burnt in these transports, they release carbon dioxide which cycles back to the nature to to be absorbed by the plants, starting the biofuel process all over again.

AI examiner evaluation

Task Achievement / Task Response — Band 6.5

The response successfully identifies the main features of the ethanol production process. You have clearly outlined the cyclical nature of the system, moving from the biological growth phase to the industrial processing phase. The inclusion of the environmental impact (carbon dioxide release and absorption) is a strong point that demonstrates a good understanding of the diagram. To reach a higher band, ensure that you explicitly mention the specific inputs and outputs at each stage, such as the role of 'enzymes' or 'yeast' if implied by the diagram, to provide a more comprehensive summary of the technical steps involved.

Coherence and Cohesion — Band 7.0

The essay is logically organized, with a clear introduction, an overview, and distinct body paragraphs that follow the chronological flow of the process. The use of cohesive devices such as 'First of all', 'The next stage', and 'In the following stages' helps guide the reader through the sequence effectively. Paragraphing is used appropriately to separate the natural growth phase from the industrial processing phase. The progression of ideas is smooth, and the connection between the final stage and the beginning of the cycle is well-articulated.

Lexical Resource — Band 6.0

You have used a sufficient range of vocabulary to describe the process, including terms like 'cyclical', 'fermentation', 'cellulose', and 'microbes'. The language is generally precise and appropriate for a technical description. There are a few minor issues, such as 'cycles back to the nature', where the article 'the' is unnecessary, and 'different range of vehicles', which is slightly unnatural. Expanding your vocabulary to include more varied verbs for process description (e.g., 'converted', 'transformed', 'facilitated') would further enhance your lexical score.

Grammatical Range and Accuracy — Band 6.5

The response demonstrates a good mix of simple and complex sentence structures. Most sentences are clear and error-free, which ensures that the information is conveyed accurately. There are a few minor grammatical slips, such as 'releases carbon dioxide' (should be 'release' to agree with 'transports') and the repetitive 'to to' in the final paragraph. However, these errors are infrequent and do not impede communication. To improve, try to incorporate more varied complex structures, such as passive voice constructions, which are particularly suitable for describing industrial processes.

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