If you know the content but do not know how much to write, let the question control the answer. The command word, number of marks, evidence provided, and precision of the wording all signal how much reasoning the examiner expects. Writing everything you know can waste time and sometimes bury the point.
Practise identifying the minimum complete answer. State the claim or result, include the necessary working or explanation, and stop when the question has genuinely been answered. Then compare with marking guidance or strong model responses to learn what completeness looks like at that level.
Use the Examinations & Assessment Hub for command words, mark allocation, and answer construction. If your knowledge is sound but marks still disappear, use I Understand the Topic but Still Lose Marks — What Is Going Wrong?