A command word is the verb at the start of an exam question that tells you what kind of answer to write. State wants a short fact, Describe wants features or what happens, and Explain wants a reason. Mixing them up is one of the easiest ways to lose marks on a question you actually understand.
Cambridge publishes definitions for these words. The meanings below paraphrase Cambridge's command words page and the command words section of the IGCSE Physics 0625 syllabus.
Definitions can differ by syllabus
Each syllabus lists the command words used in its own exams, and the list is not identical everywhere. The 0625 Physics list includes Comment, Deduce and Determine. The general Cambridge page also lists Discuss, Evaluate and Outline. Show that is common on mathematics and physics papers but is not in either of those lists, so treat it as a convention. For the exact wording, find the "Command words" section near the back of your syllabus.
The command words at a glance
| Command word | Cambridge's meaning, paraphrased | What it needs from you |
|---|---|---|
| State | Express in clear terms | A short, direct answer. No reasoning |
| Give | Produce an answer from a source or from memory | A value or fact, often read from data |
| Identify | Name, select or recognise | The item itself, not an essay |
| Define | Give a precise meaning | A tight definition using the key terms |
| Calculate | Work out from given facts, figures or information | Working and an answer with unit |
| Determine | Establish an answer using the information available | A calculation or a reading from a graph or table |
| Deduce | Conclude from available information | A conclusion you reach by linking given facts |
| Predict | Suggest what may happen based on available information | A reasoned outcome |
| Describe | State the points of a topic, giving characteristics and main features | What happens or what it looks like, in order |
| Outline | Set out the main points | Brief headline points only |
| Explain | Say why and/or how, supported with relevant evidence | A reason joined to a fact |
| Compare | Identify or comment on similarities and/or differences | Both items, point against point |
| Suggest | Apply knowledge to situations with a range of valid responses | A sensible idea using what you know |
| Justify | Support a case with evidence or argument | A claim plus the evidence for it |
| Discuss | Write about issues in depth in a structured way | Several sides, then a view if asked |
| Evaluate | Judge or calculate the quality, importance, amount or value | Strengths, weaknesses, and a judgement |
| Sketch | Make a simple freehand drawing showing key features, taking care over proportions | The right shape and labelled key points, not a precise plot |
| Show that | Not defined in the lists above | Working that arrives at the given answer |
Practical advice by word
State, Give, Identify. These are usually 1 mark each. Write the answer and stop. Extra words give the examiner more chances to find something wrong. A frequent loss: giving two answers where one was asked, with one of them contradicting the other.
Define. Usually 1 or 2 marks. Learn definitions word for word from your syllabus, because science mark schemes often credit specific key words. A frequent loss: using the term in its own definition.
Calculate and Determine. Often 2 to 4 marks. Write the formula, the substitution and the answer with a unit. In Physics 0625 mark schemes a missing or wrong unit normally costs the final answer mark unless a separate unit mark exists. Mathematics schemes may also expect an accuracy such as three significant figures, so read the question for it.
Deduce and Predict. You are not recalling an answer. You are using information given in the question or earlier parts. Point to the given information you used.
Describe. Usually 2 to 3 marks. Give the points in a clear order: what you see, what changes, and by how much if numbers are given. A frequent loss: explaining when asked only to describe, which spends time and adds nothing.
Explain. Typically 2 or more marks. One mark is often the fact and another the reason. Use because, so or therefore to join them. A frequent loss: a description with no reason.
Compare. Mention both things in the same sentence, for example "A is X whereas B is Y". Writing two separate descriptions leaves the examiner to do the comparing.
Suggest. There may be several valid answers, so the mark scheme often accepts different ideas. Use the context in the question. A frequent loss: writing a textbook fact that does not fit the situation.
Justify, Discuss, Evaluate. These are longer, often on essay or extended papers. Back each point with evidence, and if the question asks for a judgement, give one. Check the mark scheme layout: some use levels of response and not point-by-point credit.
Sketch. Include labelled axes, key points such as intercepts, and the correct shape. Do not spend time plotting exact values.
Show that. The answer is printed, so the marks are for the route. Write every step, including the unrounded value before you round, and end with the given value.
One fact, three levels
This is an invented example on the same content, not a real exam question. The topic is why a metal spoon in hot tea feels hot to the touch.
State how heat travels along the spoon. [1] Conduction.
Describe how the handle of the spoon changes. [2] The end in the tea gets hot first. The handle slowly becomes warmer until it feels hot.
Explain why the handle of the spoon becomes hot. [3] The particles at the hot end vibrate more. They pass energy to neighbouring particles by collisions. Metals also have free electrons that carry energy along the spoon quickly, so the handle warms up.
The same subject is in all three. The marks differ because State wants the name, Describe wants what is seen, and Explain wants the mechanism and the reason.
Match the answer to the marks
Look at the mark total in brackets. A one-mark question rarely needs a sentence. A three-mark Explain usually needs three distinct points. If you have written two lines for a four-mark question, you have probably not given enough. For more on how marks are shared, see how Cambridge mark schemes work.
Practise the words on real questions
Read the first word of each question before reading the rest, and underline it. Then check your answer against the official mark scheme to see whether you gave a fact, a description or a reason.
Browse the IGCSE Physics past papers or O Level Chemistry past papers, write your answers by hand and compare them with the mark scheme. Reading and downloading is free. With a free account, ExamPal marks your handwriting against the official scheme and shows where each mark came from.
Frequently asked questions
- Are command words the same in every Cambridge syllabus?
- Mostly, but not exactly. Cambridge publishes a list in each syllabus and the wording can differ slightly, so check the command words section of your own syllabus.
- What is the difference between describe and explain?
- Describe asks what happens or what something is like. Explain asks why or how, so it needs a reason, usually joined to the description with a word such as because.
- How many marks does a command word tell me to write for?
- The command word does not set the number of marks, but the mark total in brackets does. As a rule of thumb, aim for one distinct point per mark.
- What does Show that mean?
- The final answer is given in the question, so the marks are for the working that leads to it. Write each step clearly and do not just quote the answer.