Band 8.0 IELTS Writing Task 1 Model Answer

Overall Band Score: 8.0 · Cambridge IELTS 19 · 2026-08-05

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 8.0)

The diagram illustrates the cyclical process of producing the biofuel ethanol, and shows how carbon dioxide is both used and released at different stages.

Overall, the production of ethanol is a closed-loop system with 6 main stages. It begins with the growth of plants using sunlight and carbon dioxide, and ends with the use of ethanol as fuel, which in turn releases carbon dioxide back into the atmosphere to be reused by plants. The process involves both natural and industrial steps, including harvesting, pre-processing, and microbial fermentation.

In the first stage, plants and trees grow by absorbing energy from sunlight and carbon dioxide. Once mature, they are harvested using machinery. The harvested biomass then undergoes pre-processing, where it is broken down into small particles, and cellulose is extracted.

Next, the cellulose is sent for processing in an industrial facility. During this stage, it is converted into sugars. Microbes are then added to these sugars to produce ethanol through fermentation. This is the key transformation point in the cycle.

The final product, ethanol, is used as a fuel source for various forms of transport, including cars, trucks, and airplanes. A notable feature is that when ethanol is burned as fuel, it releases carbon dioxide. This carbon dioxide is then reabsorbed by growing plants, thereby completing the cycle and allowing the process to begin again.

AI examiner evaluation

Task Achievement / Task Response — Band 8.0

The response effectively covers all stages of the ethanol production cycle. You have successfully identified the main features, such as the growth of plants, industrial processing, and the final combustion phase. The inclusion of the carbon dioxide cycle adds depth to your summary, demonstrating a clear understanding of the diagram's overall purpose. The information is well-selected, and the comparison between natural and industrial stages is handled logically. You have provided a clear overview and followed the process chronologically, which makes the information easy to follow. To reach a higher band, ensure that you explicitly mention all key technical inputs or outputs shown in the diagram, such as the specific mention of 'cellulose' and 'sugars' which you have done well here.

Coherence and Cohesion — Band 8.0

The response is logically organized with a clear progression from the initial growth phase to the final consumption and recycling of carbon dioxide. Paragraphing is used effectively to separate the different stages of the process, which helps the reader navigate the text. Cohesive devices such as 'In the first stage', 'Next', and 'The final product' are used appropriately to link ideas. The flow is natural, and the referencing is clear throughout the text. There is a good balance between the introduction, body paragraphs, and the concluding summary of the cycle, ensuring that the information is presented in a coherent and structured manner.

Lexical Resource — Band 7.5

You have used a range of vocabulary appropriate for a process description, including terms like 'cyclical process', 'closed-loop system', 'biomass', 'microbial fermentation', and 'reabsorbed'. This demonstrates a good level of precision. The word choices are generally accurate and contribute to a professional tone. While the vocabulary is sufficient and precise, incorporating a few more sophisticated collocations or less common technical descriptors could further enhance the lexical range. Overall, the vocabulary is used naturally and effectively to convey the technical nature of the diagram without any errors that impede communication.

Grammatical Range and Accuracy — Band 8.0

The writing displays a good variety of complex sentence structures, such as the use of relative clauses ('which in turn releases...') and participial phrases ('thereby completing the cycle'). The grammar is highly accurate, with the majority of sentences being error-free. Punctuation is used correctly to manage the flow of information. There are no significant grammatical errors that distract the reader or cause confusion. The control over tense and subject-verb agreement is consistent throughout the response, reflecting a high level of grammatical competence suitable for this task.

See this exact question answered at other band scores — the same prompt compared across bands.

Browse more IELTS Writing model answers or get your own writing scored by the same AI examiner.