Band 4.0 IELTS Writing Task 1 Model Answer

Overall Band Score: 4.0 · IELTS Momentum Workout · 2026-11-03

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 4.0)

This diagram illustrates that shows how a mechanical arm works. Motors are attached to computer, there are total of three motors. Each motor have the different purpose. These motors are control by computer.

The first motor in the left

AI examiner evaluation

Task Achievement / Task Response: Band 2.5

The response identifies two relevant features: the computer controls three motors, and the motors have different purposes. However, it stops after beginning to describe the first motor (“The first motor in the left”), so it does not explain the arm’s main parts or how they function, such as the shoulder, elbow, wrist, gripper, or pivot. It also omits the comparison with a human arm and the alternative end-effectors. There is no overview of how the system works as a whole. The response is far below the required 150 words, which leaves the task substantially incomplete. To improve, give an overview first, then describe the key components and their functions, including relevant comparisons shown in the diagram.

Coherence and Cohesion: Band 3.5

The opening gives a basic starting point by introducing the diagram and then mentioning the computer and motors. However, the response ends abruptly with “The first motor in the left,” so there is no progression from the control system to the arm’s joints or end-effector. The ideas are presented as short, separate statements, and the relationship between them is only partly made clear. For example, “These motors are control by computer” repeats the previous point rather than advancing the description. Organise the report into a brief overview followed by a logical account of the components, moving from the base and shoulder along the arm to the gripper. Use linking phrases to show how each part relates to the next.

Lexical Resource: Band 4.5

The vocabulary is basic but includes relevant terms such as “mechanical arm,” “motors,” and “computer,” which allow the reader to recognise the topic. The phrase “different purpose” also signals that the motors have distinct functions, although the functions are not explained. The very short response provides little evidence of range, and some wording is imprecise or unnatural: “attached to computer” could be expressed as “connected to the computer,” while “the first motor in the left” is incomplete and unclear. Use the diagram’s specific labels, including “pivot,” “shoulder,” “elbow,” “wrist,” and “gripper,” and describe their functions with accurate verbs such as “rotate,” “raise,” and “flex.”

Grammatical Range and Accuracy: Band 4.5

The response uses simple sentence patterns that communicate some basic information, but it shows limited structural variety. Several grammatical errors are visible: “This diagram illustrates that shows” combines two incompatible reporting structures; “attached to computer” is missing an article; “Each motor have” has incorrect subject–verb agreement; and “These motors are control by computer” uses an incorrect passive verb form and omits an article. The final fragment, “The first motor in the left,” is not a complete sentence. These issues make parts of the description awkward or incomplete. Practise accurate simple clauses first, then add controlled complex sentences, for example, “The computer controls three motors, each of which operates a different joint.”

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.