GCSE command words explained: What evaluate, describe and analyse actually mean

Command words tell you exactly what the examiner wants you to do with your knowledge. Getting the content right but using the wrong approach for the command word is one of the fastest ways to lose marks – and it happens far more often than you'd think.

This guide breaks down every major GCSE command word, explains what each one actually means, and shows you how to shape your answer so it hits the mark scheme. These command words appear across all subjects – from Science and Geography to English and History – so once you learn them, you can apply them everywhere.

A command word is the instruction at the start of an exam question that tells you how to answer. It is not the topic of the question – it is the type of response the examiner expects. Two questions can be about the same topic but require completely different answers depending on the command word used.

For example, "Describe the process of photosynthesis" and "Explain why photosynthesis is important" are about the same topic but need different approaches. The first asks you to say what happens. The second asks you to say why it matters. Miss that distinction and you will lose marks even if your science knowledge is spot on.

State means give a short, factual answer with no explanation needed. Think of it as the most direct command word – the examiner just wants the fact.

What examiners expect: A brief, accurate response. One word or one sentence is usually enough. Do not waste time explaining or justifying.

Example question: State the formula for calculating speed. Example answer: Speed = distance / time.

Outline means give the main points or key features without going into full detail. It sits between state and describe – you need more than a one-word answer but less than a full walkthrough.

What examiners expect: A summary that covers the main steps or features. Keep it concise but make sure you hit every key point.

Example question: Outline the stages of the water cycle. Example answer: Water evaporates from the surface, rises and condenses to form clouds, then falls as precipitation. It collects in rivers and lakes before the cycle repeats.

Describe means say what happens or what something is like. You are giving an account of something – think of it as painting a picture with words. You do not need to say why it happens.

What examiners expect: A clear, detailed account. Include specific facts, figures, or features. If there is a graph or diagram in the question, refer to the data directly.

Example question: Describe the trend shown in the graph. Example answer: As temperature increases from 20 to 60 degrees, the rate of reaction increases steadily. Above 60 degrees the rate drops sharply.

Explain means say what happens and why. This is where most marks are lost. Many students describe when they should be explaining – they state the facts but forget to give the reasons behind them.

What examiners expect: A clear account plus the reasoning. Use words like "because", "this means that", "as a result", and "due to" to show you are linking cause and effect.

Example question: Explain why the rate of reaction increases with temperature. Example answer: As temperature increases, particles gain more kinetic energy and move faster. This means they collide more frequently and with greater force, so more collisions exceed the activation energy. As a result, the rate of successful collisions increases.

Compare means identify the similarities and differences between two or more things. You must cover both – just listing features of each item separately is not comparing.

What examiners expect: direct, side-by-side points that explicitly link the things being compared. Use phrases like "both", "whereas", "in contrast", and "similarly".

Example question: Compare the structure of animal and plant cells. Example answer: Both animal and plant cells contain a nucleus, cell membrane, and cytoplasm. However, plant cells also have a cell wall and chloroplasts, whereas animal cells do not. Plant cells have a permanent vacuole, while animal cells either lack one or have small temporary vacuoles.

Analyse means break something down into its parts and examine how they relate to each other. You are looking at the detail, identifying patterns, and drawing out what the evidence shows.

What examiners expect: A structured examination that goes beyond surface-level description. Identify patterns, trends, or relationships in the information. Support your points with evidence from the data or source material.

Example question: Analyse the data in the table to determine the effect of light intensity on photosynthesis. Example answer: The data shows that as light intensity increases from 1 to 5 arbitrary units, the rate of photosynthesis rises from 2 to 10 bubbles per minute – a proportional increase. Beyond 5 units the rate plateaus at 10 bubbles per minute, suggesting that light is no longer the limiting factor and another factor such as carbon dioxide concentration or temperature is restricting the rate.

Evaluate means weigh up the evidence and come to a supported judgement. This is one of the higher-demand command words – you need to consider different sides and then say what you think overall, backed by reasoning.

What examiners expect: A balanced discussion of strengths and weaknesses, advantages and disadvantages, or arguments for and against. Crucially, you must finish with a clear conclusion or judgement.

Example question: Evaluate the use of renewable energy sources to generate electricity. Example answer: Renewable energy sources such as wind and solar do not produce carbon dioxide during operation, which helps reduce climate change. They also use resources that will not run out. However, they can be unreliable – wind turbines only generate power when it is windy, and solar panels are less effective on cloudy days. The initial cost of installation is high. Overall, renewable sources are an important part of reducing carbon emissions, but they currently need to be supplemented by other sources to ensure a reliable energy supply.

Justify means give reasons to support a conclusion or decision. Unlike evaluate, you are not weighing up both sides – you are making a case for one particular position and backing it up.

What examiners expect: A clear statement of your position followed by logical reasons and evidence that support it.

Example question: Justify the use of a catalyst in industrial ammonia production. Example answer: Using an iron catalyst in the Haber process lowers the activation energy, allowing the reaction to proceed at a lower temperature. This reduces energy costs significantly. Without the catalyst, much higher temperatures would be needed, making the process less economically viable and increasing carbon emissions from fuel use.

Suggest means use your knowledge to propose an answer to something that may not have a single right response. The examiner is testing whether you can apply what you know to an unfamiliar situation.

What examiners expect: A reasonable, scientifically sound proposal. You do not need to be certain – the question is deliberately open-ended. Use your understanding of the underlying principles to construct a plausible answer.

Example question: Suggest why the plant in the dark cupboard grew taller but had yellow leaves. Example answer: Without light the plant could not photosynthesise, so it could not produce glucose for energy. It may have grown taller as it stretched towards any available light source. The yellow leaves suggest a lack of chlorophyll production, which requires light.

Calculate means work out a numerical answer using the information given. You must show your working – even if you get the final number right, you can lose marks if you do not show how you got there.

What examiners expect: A clear mathematical process with the correct answer and appropriate units. Write out the formula, substitute the values, then calculate. Always include units in your final answer.

Example question: Calculate the kinetic energy of a 2 kg object moving at 3 m/s. Example answer: KE = 0.5 x m x v squared = 0.5 x 2 x 3 squared = 0.5 x 2 x 9 = 9 J.

Discuss means explore a topic from different angles, considering multiple viewpoints or factors. It is similar to evaluate but does not always require a final judgement – sometimes the examiner just wants to see that you can consider the complexity of an issue.

What examiners expect: A balanced exploration covering different perspectives, factors, or arguments. Reference evidence where possible and show awareness that issues can be more nuanced than they first appear.

Example question: Discuss the ethical issues surrounding genetic engineering. Example answer: Genetic engineering can be used to treat genetic diseases by replacing faulty genes, which could dramatically improve quality of life for patients. However, some people argue that modifying human DNA crosses an ethical boundary and could lead to "designer babies" selected for non-medical traits. There are also concerns about long-term effects that are not yet fully understood. From a scientific perspective the technology has enormous potential, but society needs to carefully consider where the boundaries should be drawn.

The most common mistake is describing when the question asks you to explain. Students write a perfectly accurate account of what happens but never say why – and the examiner cannot award the explanation marks. Always check the command word before you start writing.

Another frequent error is evaluating without a conclusion. If a question says evaluate, the examiner is specifically looking for a judgement at the end. You can write a brilliant balanced discussion, but if you do not finish with "overall" or "on balance", you will miss the top marks.

Compare questions also catch students out. Many students describe item A, then describe item B, but never directly link them. Use comparative language – "whereas", "in contrast", "both" – to show you are making direct comparisons rather than writing two separate descriptions.