Band 8.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 8.5 · Cambridge IELTS 19 · 2026-07-27

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 8.5)

The diagram illustrates the step-by-step process of producing biofuel ethanol from biological matter.

Overall, ethanol production is a cyclical multi-stage process involving biological growth, mechanical harvesting and processing, chemical treatment, and ultimate utilization as fuel, which releases carbon dioxide back into the atmosphere.

Initially, plants and trees utilize sunlight and carbon dioxide to grow. Once fully grown, this biomass is harvested using specialized machinery and transported to processing facilities. In the next stage, the harvested vegetation undergoes shredding to break it down into smaller, manageable fragments.

Following shredding, the plant material is subjected to chemical processing, where it is converted into cellulose. Microbes are then added to ferment the cellulose, transforming it into liquid ethanol. In the final stages, the purified ethanol is transported to fueling stations, where it powers vehicles such as cars and trucks. The combustion of this fuel releases carbon dioxide back into the air, completing the cycle as plants absorb it for growth once again.

AI examiner evaluation

Task Achievement / Task Response — Band 8.5

The response effectively covers all stages of the ethanol production process as depicted in the diagram. You have successfully identified the main features, starting from the growth of biomass through to the final combustion stage. The overview is clear and provides a good summary of the cyclical nature of the process. You have accurately described the sequence of events, including the mechanical and chemical stages. The information is well-selected and presented in a logical order, fulfilling the requirements of the task by reporting the key stages without unnecessary detail. The response is accurate and provides a comprehensive overview of the process.

Coherence and Cohesion — Band 8.5

The response is logically organized, with a clear introduction, an overview, and body paragraphs that follow the chronological order of the process. The use of cohesive devices such as 'Initially', 'Once', 'In the next stage', 'Following', and 'In the final stages' creates a smooth flow of information. Paragraphing is used effectively to separate the different phases of the production cycle. The progression of ideas is clear throughout the text, and referencing is accurate, ensuring that the reader can easily follow the steps described in the diagram. The structure is coherent and easy to follow.

Lexical Resource — Band 8.0

You have used a good range of vocabulary appropriate for a process description, such as 'cyclical', 'biomass', 'shredding', 'ferment', and 'combustion'. The word choice is precise and contributes to the clarity of the explanation. There are no significant errors in word choice or collocation. While the vocabulary is functional and accurate, incorporating a few more sophisticated or varied synonyms for common process verbs could elevate the response further. Overall, the lexical range is sufficient to convey the information clearly and effectively.

Grammatical Range and Accuracy — Band 8.5

The response demonstrates a good command of grammatical structures. You have used a mix of simple and complex sentences effectively, such as 'Once fully grown, this biomass is harvested...' and 'Microbes are then added to ferment the cellulose, transforming it into liquid ethanol.' The punctuation is accurate, and there are no noticeable grammatical errors that impede communication. The use of passive voice, which is appropriate for describing a process, is handled well throughout the text. The writing is fluent and error-free, reflecting a high level of grammatical control.

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