Edexcel IGCSE Physics: Command words and keywords

Pearson Edexcel International GCSE Physics (4PH1) uses the command words defined in the specification. Mark schemes follow the same science principles: correct terminology, working and units are essential. Point-marked and levels-based questions are used.

Command words in Edexcel Physics 4PH1

Point-marked questions

Command word	What to do	Common mistake
State / Name / Give	Recall; short answer	Overwriting
Identify	Choose from information given	Adding explanation
Define	Precise meaning (often with equation)	Vague
Calculate	Work out; show working; units	Missing units
Show that	Prove given value with calculation	No working
Determine	Numerical answer with working	Guess
Plot	Graph; line of best fit; labelled axes	Wrong scale
Draw	Circuit/ray diagram; correct symbols	Wrong symbols
Sketch	Rough graph/diagram; key features	Too detailed
Describe	What happens; no “why”	Adding explanation
Explain	Why or how; use “because”	Only describing
Give a reason	Say why; only the number asked	Too many
Suggest	Apply to new context	Textbook recall
Predict	What will happen	Unsupported
Compare	Similarities and differences	No comparative language

Levels-based questions

Command word	What to do	Common mistake
Evaluate	Judge; conclude with evidence	No conclusion
Assess	Judge importance; conclude	Description only
Discuss	Explore aspects; conclude	One-sided
Justify	Support with evidence	Unsupported

Keywords examiners look for

Mechanics

Term	Use correctly	Avoid
Speed	Distance / time; scalar	Velocity
Velocity	Displacement / time; vector	Speed
Acceleration	Change in velocity / time	”Getting faster”
Force	N	Wrong unit
Weight	mg; N	Mass (kg)
Mass	kg	Weight (N)
Momentum	mv; kg m/s	Wrong unit
Work done	F × d; J	”Effort”
Power	Energy / time; W	”Strength”
Efficiency	(useful / total) × 100%	Wrong formula
Resultant force	Net force	Single force
Equilibrium	No resultant force; no resultant moment	”Balanced”

Energy and thermal physics

Term	Use correctly	Avoid
Kinetic energy	½mv²	Wrong formula
Gravitational potential energy	mgh	Wrong formula
Specific heat capacity	Energy for 1 kg, 1°C	”Heat capacity”
Specific latent heat	Energy for change of state	”Latent heat”
Conduction	Through solids	Convection
Convection	In fluids	Conduction
Radiation	Infrared; no medium	Conduction
Conductor	Allows heat/electricity	Insulator
Insulator	Poor conductor	Conductor

Waves

Term	Use correctly	Avoid
Amplitude	Max displacement	”Height”
Frequency	Hz	”Speed”
Wavelength	m; one cycle	”Length”
Reflection	i = r	Wrong law
Refraction	Change in speed	”Bending” only
Critical angle	Angle for 90° refraction	Wrong
Total internal reflection	Angle > critical	Incomplete
Longitudinal	Vibration
Transverse	Vibration ⊥ travel	Longitudinal

Electricity and magnetism

Term	Use correctly	Avoid
Current	A	”Flow”
Potential difference	V	”Voltage” (Pd preferred)
Resistance	V/I; Ω	Wrong formula
Ohm’s law	V = IR	Wrong conditions
Series	Same current	Parallel
Parallel	Same pd	Series
e.m.f.	Energy per unit charge from source	Pd
Magnetic field	Region of force	Vague
Electromagnetic induction	Induced e.m.f.	Wrong context

Nuclear physics

Term	Use correctly	Avoid
Alpha	⁴₂He	Beta
Beta	⁰₋₁e	Alpha
Gamma	EM wave	Particle
Half-life	Time for half to decay	”Half the time”
Ionisation	Removal of electrons	”Radiation”
Irradiation	Exposed to radiation	Contamination
Contamination	Radioactive material on/in body	Irradiation

Edexcel marking principles

• Apply positively—reward what candidates show.
• Method marks—awarded for correct working even if final answer wrong.
• Units—required; check conversions.
• Best-fit for levels-based questions.
• Working—must be shown for calculations.

What examiner reports highlight

• Weight vs mass—weight in N, mass in kg.
• Formula errors—wrong equation (e.g. KE = mv²).
• Units—missing or wrong.
• Describe vs Explain—description when explanation required.
• Suggest—generic answers instead of application.
• Circuit symbols—wrong or misdrawn.

Tips for Edexcel Physics 4PH1

1. Learn formulae with correct symbols and units.
2. Show working in every calculation.
3. Check units before and after substitution.
4. For Give a reason—only the number asked for.
5. For Suggest—apply to the specific scenario.
6. Past papers + mark schemes show acceptable wording.

How Tutopiya helps

Tutopiya supports Edexcel IGCSE Physics with tutors who use the 4PH1 specification and past papers. Explore IGCSE resources or book a free trial.

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Based on Pearson Edexcel International GCSE Physics 4PH1 specification. Check the latest specification for your exam series.