Band 4.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 4.5 · IELTS Momentum Workout · 2026-10-12

IELTS Writing Task 1 question

The diagram below shows how a mechanical arm works, and how the joints that make up the arm function in the same way as those in a human arm. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

Student answer (Band 4.5)

The diagram explains the process that how a mechanical arm works, and how the joints that make up the arm function in the same way as those in a human arm

Overall,mechanical arm consists of different parts just like a human arm.Functions of all parts are controlled by motors and motors are basically operated by computer.Moreover, hand drills ,spray paints, and welding machines follows the same mechanism.

Mechanical arm consists of a base that may be stationary or movable.

Its differents parts are controlled by 3 motors.2 motors are present at the elbow joint that allow movements.Third motor acts like a gripper. some other parts like

a shoulder , a wrist , and an elbow are used for different purposes.

Mechanical arm is used in different machines that are used to perform a variety a tasks like a drilling ,spraying paint and welding metal

AI examiner evaluation

Task Achievement / Task Response: Band 4.5

The response identifies the diagram’s general subject and mentions the base, computer-controlled motors, and alternative uses such as spraying, drilling and welding. However, it reports the mechanism inaccurately: the diagram shows three motors, but not “2 motors … at the elbow”; the elbow is a joint that allows movement, while the motors connect to different parts. The shoulder, pivot, wrist and gripper are named but their functions are mostly not explained, and there is no clear account of how the arm’s components work together or how they compare with human joints. The response is also below the required 150 words; 25 words copied from the prompt were not counted. Add a fuller, accurate description of the labelled parts and their functions.

Coherence and Cohesion: Band 4.0

There is a basic overall structure: an opening, a general overview, and further details about the base and possible applications. This gives the reader some sense of the topic. However, the progression is limited, and the final paragraph repeats the applications already mentioned in the overview rather than developing the explanation. The sentence about “some other parts” lists the shoulder, wrist and elbow without connecting each part to its function, so relationships between ideas remain unclear. Paragraphing and spacing are inconsistent, and linking is sparse. Organise the response in a clearer sequence—for example, control system and base first, then the joints and end-effector—and use concise links to show how the parts relate.

Lexical Resource: Band 5.5

The response uses some relevant task vocabulary, including “mechanical arm,” “motors,” “elbow joint,” “gripper,” “stationary or movable,” and “welding metal.” These terms show an adequate basic range for describing the diagram. However, vocabulary is repetitive and several choices or forms are inaccurate, such as “different machines that are used to perform a variety a tasks” and “hand drills, spray paints.” “Third motor acts like a gripper” also confuses the motor with the component it controls. Use more precise labels from the diagram, such as “pivot,” “shoulder,” “wrist,” and “alternative end-effectors,” and choose natural task collocations. Check spelling and word forms, including “different” and “variety,” to make the description clearer.

Grammatical Range and Accuracy: Band 4.5

The response attempts a few longer structures, including “The diagram explains the process…” and “Mechanical arm is used in different machines that are used…,” but most sentences follow simple patterns and control is inconsistent. Errors include the opening construction “the process that how,” missing articles in “Mechanical arm consists of a base,” and subject–verb disagreement in “welding machines follows.” The sentence “Third motor acts like a gripper” also lacks an article, while punctuation and spacing around commas and full stops are unreliable. These errors sometimes make relationships between parts difficult to follow. Practise accurate simple sentences first, then combine them with clauses such as “which allows…” to explain each component’s function; check articles, agreement and sentence boundaries during editing.

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