Band 4.0 IELTS Writing Task 1 Model Answer

Overall Band Score: 4.0 · Cambridge IELTS 19 · 2026-10-31

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 4.0)

The diagram outline the stages of producing biofuel known as ethanol from the plants and how carbon dioxide circulates through out the cycle.

In the first stage, plants and trees grow by absorving sunlight and carbon dioxide. When they mature, then harvested using of machine. The harvested products transform into pre-processing and produce cellulose. Next, the cellulose is processing

AI examiner evaluation

Task Achievement / Task Response: Band 3.0

You identify the topic and begin describing the early stages, including plant growth, harvesting, pre-processing and cellulose. However, the response stops before explaining the later stages—processing into sugars, the addition of microbes, ethanol production, its use in transport, and the return of carbon dioxide to plants. It also gives no clear overview of the complete cycle. The description is therefore only a minimal response to the task, and the stated length requirement is not met: the response contains 59 words rather than at least 150. To improve, cover the full sequence and highlight the cycle linking carbon dioxide released during fuel use with plant growth.

Coherence and Cohesion: Band 4.5

The response has a basic chronological direction, signalled by phrases such as “In the first stage” and “Next,” so the reader can follow the opening steps. However, it ends abruptly at “the cellulose is processing,” leaving the sequence incomplete and preventing a clear overall progression. There is also no separate overview or paragraphing to distinguish the cycle’s main features from its stages. Some links are awkward, as in “When they mature, then harvested,” where the relationship between maturity and harvesting is not clearly expressed. Organise the process from beginning to end, use a small number of accurate sequencing links, and finish by explaining how carbon dioxide returns to the plants.

Lexical Resource: Band 4.5

You use several relevant process terms, including “biofuel,” “carbon dioxide,” “harvested,” “cellulose” and “cycle,” which show some task-specific vocabulary. However, the range is limited because the response covers only the early stages, and some word choices or forms are inaccurate: “outline” should be “outlines,” “absorving” is misspelled, and “the harvested products transform into pre-processing” does not clearly describe the process. “Products” is also vague for the plant material shown. Use precise process language and collocations, such as “the crops are harvested,” “the material undergoes pre-processing,” and “cellulose is converted into sugars.”

Grammatical Range and Accuracy: Band 4.5

The response attempts both a longer opening sentence and a sequence of process statements, but grammatical control is inconsistent. For example, “The diagram outline” has a subject–verb agreement error, while “When they mature, then harvested using of machine” is missing a clear subject and auxiliary and has an incomplete construction. The final clause, “the cellulose is processing,” also uses the wrong passive form; it should be “the cellulose is processed.” These errors make parts of the process difficult to understand. Practise accurate passive structures, which are especially useful for describing diagrams, and check that each sentence has a complete subject and verb. A wider range of correctly formed sentences would improve clarity.

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

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