For Pearson Edexcel International GCSE English Language A, Assignment B is assessed through writing objectives. AO4 assesses whether students communicate clearly, effectively and imaginatively by selecting and adapting tone, style and register for different forms, purposes and audiences. AO5 assesses whether students use a range of vocabulary and sentence structures for clarity, purpose and effect, with accurate spelling and punctuation.
A strong Assignment B question must therefore name or make clear the writing purpose, intended audience and required form, such as a letter, speech, article or report. It should also give students enough scope to choose an appropriate tone, style and register, develop ideas imaginatively, and shape the writing for its intended effect.
The question should allow evidence of both objectives: AO4 through purposeful communication and adapted form, tone, style and register; AO5 through varied vocabulary and sentence structures, clear expression, and accurate spelling and punctuation. Analysis of a source text may help students generate ideas, but analysing textual evidence is not itself what AO5 assesses.
Use the wording of the requirement as a checklist: Can students identify the purpose, audience and form? Can they make deliberate choices about tone, style and register? Can they develop ideas with vocabulary and sentence structures chosen for clarity, purpose and effect? Do not treat the requirement as information to memorise and repeat.