Band 6.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 6.5 · Cambridge IELTS 19 · 2026-09-16

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 digram illustrates the production of biofuel, also know as ethanol.

Overall, it is evident that the production of ethanol is a cyclical process. It consist of several stages including growing, harvesting, pre-processing, processing and introduction of microbes.

At the initial stage, plants and trees absorb sunlight and carbon dioxide as a form of energy to grow. After this, the grown plants and trees are harvested. Following this, the harvested plants and trees are crushed and prepared for processing. Cellulose was produced at this stage.

Next, cellulose undergoes a chemical process to synthesis sugars. Subsequently, microbes are introduced to the sugars. At this stage, fementation takes place and ethanol is produced. The produced biofuel can be use as source of energy for movement by cars, lorries and air planes. Carbon dioxide is released into the atmosphere by vehicles and air planes after use, which is absorbed by trees and plants, then the cycle continues.

AI examiner evaluation

Task Achievement / Task Response — Band 7.0

The student successfully covers all key stages of the process shown in the diagram, from energy absorption and harvesting through to pre-processing, sugar production, microbe addition, and the creation of ethanol used by various vehicles and converted back into carbon dioxide. An overview is provided in the second paragraph, correctly identifying the cyclical nature of the process. The main features are reported accurately with no significant omissions or invented data. However, there are minor lexical inaccuracies in describing the stages, such as stating 'Cellulose was produced at this stage' when the diagram indicates cellulose is an intermediate input/output entity. Despite this minor point, the task is fully addressed in line with Band 7 requirements.

Coherence and Cohesion — Band 6.5

The response has a clear overall progression, starting with an introduction and overview, moving chronologically through the process, and concluding with the cyclical return of carbon dioxide. Paragraphing is used appropriately to separate the introduction, overview, and body details. Cohesive devices are employed to link stages, such as 'At the initial stage', 'After this', 'Following this', and 'Subsequently'. However, some cohesive links feel slightly repetitive or mechanical (e.g., the heavy reliance on 'After this' and 'Following this'). Reference pronouns and logical transitions are generally clear, enabling the reader to follow the sequence without difficulty. Overall, this demonstrates the characteristics of a Band 6.5 to 7.0 performance.

Lexical Resource — Band 6.0

The student demonstrates an adequate range of vocabulary for the task, successfully using process-related terms such as 'cyclical process', 'harvested', 'pre-processing', 'chemical process', and 'fermentation'. There are, however, a few spelling and word-choice errors, notably 'digram' instead of 'diagram', 'know' instead of 'known', 'consist' instead of 'consists', 'synthesis' instead of 'synthesise', 'fementation' instead of 'fermentation', and 'air planes' instead of 'airplanes'. While these errors do not impede communication, they prevent the lexical score from reaching higher bands. The use of less common vocabulary is attempted with mixed accuracy.

Grammatical Range and Accuracy — Band 6.0

The response features a mix of simple and complex sentence structures, such as passive constructions ('ethanol is produced', 'microbes are introduced') and relative clauses ('which is absorbed by trees'). There are several grammatical and mechanical errors throughout the text, including subject-verb agreement issues ('It consist of') and tense shifts ('Cellulose was produced at this stage' followed by present tense verbs). Punctuation and word spacing are occasionally flawed ('air planes', 'lorries'). Although these errors are noticeable, they rarely impede overall communication, placing the response solidly in the Band 6 category.

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

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