I have been reading through a sample recently (from AQA, OCR and WJEC - they are freely downloadable from examinations' board websites) in part to help a student prepare for a November exam in English, and in part to provide material for this survey.
So what follows here is a brief account of recurrent themes, and an abstract of the most useful or commonest advice.
First, there are the comments that could apply to a range of subjects, not just English. Exam technique is the issue here. Straying away from the terms of the question is a commonly-observed fault. This comprises a spectrum from 'rubric error', an absolute 'singing from the wrong hymn-sheet', to a much more common practice of beating about the bush or approximating an answer to a carefully-worded and specified question.
If there is a lesson here, it is that GCSE questions are purposely specific - and require targeted answers.
Comments on poor distribution of effort (writing at length for just a handful of marks, or very little for a question requiring development), and non-existent or nugatory planning of answers to heavily-weighted questions, also belong to the category of exam technique and will apply to subjects besides English.
But for the rest I will turn to examiners' remarks on the desired quality of the English that is the focus of the GCSE exam.
I will list these for convenience under three general heads of strategy, method and finish.
By strategy I mean the way that examiners consider how questions of a particular structure and wording are best approached. Three italicised examples below will illustrate.
i/ 'Describe a sea-side scene on an autumn afternoon...
A good strategy is to adopt the pose of a detached observer (cf a magazine journalist out to capture local colour) - a bad strategy is write a first person narrative.
ii/ 'What are the thoughts and feelings of X before, during and after his experience ...
A good strategy is to track the text closely and work methodically through the development. (A poor strategy is any departure from this.)
iii/ Compare Text A with Text B by analysing the effects of the writers' use of language.
Acknowledging that this is difficult skill, a good stategy is to cross reference or alternate in the discussion of details - A1 with B1; A2 with B2 etc.
No strategy demands a long answer - as one report states: Candidates can achieve very high marks within a very few pages.
By method I mean the way points are scored, and consequently marks awarded, within the chosen strategy. Here the constant refrains of the examiners are: 'Be specific, not general, be detailed, not sweeping, be authentic and personal, not vague or remote, be choosy in vocabulary, not lazy; when quoting, select the key words or pithy phrases, not lengthy sentences; when analyzing, don't simply point to a feature, but explain its effect. '
For many candidates such exhortations will have been heard from their teachers, and be easier said than done. Not all will have the knowledge of current affairs to supply telling real instances where arguments are to be made - not all will have the extensive vocabulary with which to describe things memorably, or the lively imagination to find an unusual angle. But at least everyone can gather the direction in which to aim.
Finish refers to correctness in the mechanics of writing, - spelling, punctuation, grammar and so forth - 'technical accuracy' or 'technical control' in the language of the examiners, for which a third of the marks are awarded. Errors could be avoided by simple checking - one comment reads - to which I would reply that checking for many students is not so simple. But it is nevertheless important - a skill to be seriously worked on.
Some examples of the use of English which examiners currently disapprove of may be noted here: 'program' for programme and 'tele' for television. The right use of 'there', 'their' and 'they're' - and ''your and 'you're' - almost function as tests within the exam - for who can avoid them?
All errors are not equal - a letter left out in the spelling of a long and perhaps uncommon word does not equate in seriousness with an unwarranted change in tense, or a sequence of sentences undivided by full stops. Errors are the equivalent of noise in communications - therefore the fewer (or the less) the better.