Many Science marks in Punggol are lost because students know the topic but answer the wrong task. A learner may explain when asked to describe, discuss only one side when asked to compare, or give a guess when asked to predict from evidence. Understanding Science command words is therefore part of exam performance from Primary Science and PSLE through Secondary G1, G2 and G3.
Parents searching for Science answering techniques, how to answer Science questions, PSLE Science open-ended questions or Secondary Science exam technique are usually trying to solve the same conversion problem: the child has some knowledge, but the response does not match what the question asks.
This guide belongs to the Science Improvements In Punggol lane and works with How to Read Science Questions, Diagrams, Graphs and Technical Vocabulary, the PSLE Science revision and open-ended answer guide, and Science Tuition Punggol.
The command-word map
- State / Name / Identify: give the required fact or item clearly.
- Describe: say what happens or what the evidence shows.
- Explain: give the scientific reason or mechanism.
- Compare: write directly about similarities and/or differences.
- Predict: give a plausible outcome based on evidence or a known relationship.
- Suggest: apply knowledge to a new situation and give a plausible response.
- Justify: support a choice with evidence or scientific reasoning.
- Evaluate: judge using evidence, strengths, limitations or criteria.
Cambridge International and AQA Science both publish command-word guides that make the same fundamental point: the command tells the student what kind of response is required. Singapore assessments have their own syllabus and marking requirements, but this reading habit transfers well.
State: give the fact and stop
A state question usually needs a brief response. Students often lose time by writing everything they know around the answer. If the task asks for a term, variable, observation or fact, answer precisely and do not add an unnecessary mechanism.
Describe: report the pattern
Describe questions focus on what is happening. With a graph or table, name the variables and state the relationship accurately. Use values when they strengthen the description. Do not jump to the reason unless the question asks for it.
Explain: build the causal chain
A useful internal scaffold is condition → concept → mechanism → outcome. The student identifies what changed, selects the scientific idea, explains how it acts in that situation, then completes the outcome.
For deeper training, use How to Answer Explain Questions in Exams.
Compare: write about both sides
Compare questions are stronger when written in paired form: A is higher than B; both have X, but only A has Y; A increases while B remains approximately constant. Separate mini-essays about A and B can hide the comparison.
Predict: use a relationship, not a guess
A prediction should follow from a trend, scientific model or relationship. Ask what evidence is already available, what changes, and whether the prediction stays within a sensible scientific boundary.
Suggest: transfer known Science to a new case
Suggest questions often place familiar Science inside an unfamiliar context. The student should identify the evidence, retrieve a relevant scientific relationship and give a plausible response that fits both.
Justify and evaluate: make the evidence do work
A justification supports a decision. An evaluation judges against a criterion. Strong answers use the information supplied, relevant scientific principles, and clear limitations rather than repeating the conclusion in different words.
Command word + evidence + condition
Before writing, students can mark three things: the command word that defines the job, the evidence they must use, and the condition that changes the scientific situation. This reduces answers that are scientifically related but do not answer the actual question.
Primary 3–4
Keep the distinctions simple: state means tell me; describe means tell me what happens; explain means tell me why; compare means tell me how both are similar or different. Use the same diagram with different command words so the child sees how the answer changes.
Primary 5–6 and PSLE
Command words help control answer length and completeness. A state question should not consume the time of an explanation question, while an explain question should not stop at a keyword. Use the Primary 5–6 and PSLE guide for the broader system.
Secondary G1, G2 and G3
Secondary Science adds command words tied to data, calculation, practical planning and evaluation. Students should be able to switch between state, describe, explain, calculate, determine, justify, evaluate, design and suggest without treating them as interchangeable.
A 15-minute command-word drill
- Choose one diagram, graph or experimental setup.
- Write six questions using six different command words.
- Answer each in the shortest complete form.
- Compare how the response changes when only the command word changes.
- Log the command word that still causes errors.
Common mistakes
- explaining when asked to describe;
- describing without giving the reason;
- comparing only one item;
- predicting without evidence;
- suggesting something that contradicts the known Science;
- justifying by repeating the choice;
- evaluating without a clear criterion;
- writing far more than the task requires.
When tuition adds value
In eduKate Punggol’s three-student Science tutorials, the tutor can keep the scientific content stable while changing the command word. Students then experience the difference between describing, explaining, comparing, predicting and justifying using the same evidence. That feedback is more useful than memorising a list of command-word definitions.
Parents can review Science Tuition Punggol or the Science tuition sign-up route.
FAQ
What is the difference between describe and explain in Science?
Describe tells what happens or what the evidence shows. Explain gives the scientific reason or mechanism for why it happens.
How do you answer compare questions?
Make direct paired statements about both items, using similarities and/or differences as required.
What does suggest mean?
Apply existing Science and the information provided to propose a plausible response in a new situation.
Conclusion
A good Science answer begins before the first sentence. Read the job first. State briefly. Describe accurately. Explain causally. Compare both sides. Predict from evidence. Suggest plausibly. Justify with support. Evaluate against a criterion.
Explore the Punggol Science reading library for related guides.
