IGCSE command words: what each one actually wants

Two answers can contain the same facts and score completely different marks — because the question asked for one thing and the answer gave another. Command words are the instruction, not decoration. Read the word first, then decide what to write.

This guide applies across Cambridge IGCSE subjects, including Chemistry, Physics and Business Studies. The command word sets the ceiling on what a mark scheme can award, regardless of subject — a perfectly correct fact, given in answer to the wrong instruction, still loses the mark.

State

A short, precise answer with no working and no reasoning. One fact, one line. Adding an explanation costs time and earns nothing extra — but leaving out a required unit or a required number of items (the question often says "state two") drops marks that a fuller-sounding answer would have kept.

Define

Give the precise meaning of a term, in a way that would still be true if you swapped in a different example. A definition that only works for the specific instance in the question is really a description, not a definition, and mark schemes usually catch that distinction.

Describe

Say what happens, in order, without explaining why. This is where most marks are lost going the other way: students launch straight into reasoning ("this happens because …") when the question hasn't asked for a cause yet. Describe the trend, the sequence, or the process first — the "why" question, if there is one, comes separately.

Explain

Give a reason, and connect it clearly to the outcome using a causal link (because, therefore, this means that). A list of correct facts with no linking word between them is a description wearing an explanation's name — mark schemes for "explain" specifically reward the connective reasoning, not just the facts either side of it.

Suggest

Apply what you know to a situation the syllabus hasn't given you a memorised answer for. There's rarely one single correct response; the mark goes to a plausible, well-reasoned idea grounded in the topic, not to guessing what the examiner "wants to hear."

Calculate

Show the working, not just the final number. Method marks exist precisely so that a correct approach with one arithmetic slip still scores most of the marks — but only if the working is visible on the page. An unsupported final answer, even a correct one, can lose marks it would otherwise have kept.

Compare

State a similarity or difference explicitly, in the same sentence, for both things being compared. Two separate paragraphs — one describing each thing on its own — is a common way to lose "compare" marks even when both descriptions are individually correct, because nothing on the page actually compares them.

Justify

Support a choice, opinion, or decision with reasoning — usually after the question has already asked you to make that choice. The mark rewards the quality of the argument for the option chosen, not whether it's the "best" option in the abstract.

Evaluate

Weigh up more than one side and reach a supported judgement. A list of advantages followed by a list of disadvantages, with no comparison between them and no final conclusion, typically scores as two one-sided arguments rather than a genuine evaluation — the weighing-up step at the end is where the top marks usually sit.

Discuss

Present more than one viewpoint on an issue where reasonable people could disagree. Similar to Evaluate, but the emphasis is on setting out the different angles fairly rather than necessarily landing on one final verdict.

The same word, three subjects

"Evaluate" in Business Studies marketing might mean weighing up two pricing strategies against a stated business objective. "Explain" in Chemistry stoichiometry means connecting a mole-ratio calculation to why it gives the answer it does, not just showing the arithmetic. "Describe" in Physics motion, forces and energy means reading a graph's shape and stating what it shows — speeding up, constant speed, slowing down — before any question about why it does that. The command word is constant; what counts as satisfying it depends on the subject content around it.

Command words tell you the shape of the answer. The subject content still has to be right — that's what the free topic pages on Chemistry, Physics and Business Studies are for, and each one ends with a recall checklist to test whether the content has actually stuck.

Then practise the command words where they actually appear: on real exam questions. Every past paper comes with its mark scheme, so you can check what earned the marks — Chemistry, Physics, Business Studies and Mathematics.