A brief description of secondary education in England (and Wales?)
Children go to secondary school in the September of the academic year they will turn 12. So, most children are 11.
DD had three years of a broad education, then chose her GCSE options in year 9 (aged 13)
When she took her GCSEs 10 subjects were the norm in her school. The compulsory options in her school were: Maths, English language, English literature, Citizenship, Science (biology, chemistry and physics)
She then chose art, geography and history as her extra options (because she took triple science)
Her school does the GCSE syllabus over two years, so she started her GCSEs in year 10 at age 14 . Students take their GCSEs at the end of year 11 (May/June) – most of them are 16. Only the students with summer birthdays are still 15.
GCSEs are graded 1 to 9, with 9 being the highest pass. A low pass at GCSE is a 4. To do A levels at DD’s school the students required a 6 or higher to take a particular subject at A level. Most employers want maths and English GCSEs as a minimum which is why students are encouraged to retake them until they pass.
Most students take 3 subjects at A level. A levels are linear so they have to remember two years’ worth of work to do well. Only the most able of students take 4 subjects. The students at DD’s school who achieved low passes at GCSE didn’t do very well at A level.
Due to the enormous content of GCSE courses your friend’s son needs to learn the syllabus over two years.
I hope this helps