Not an expert, but did DIY DD for last test.
there are some multiple choice type questions e.g you are given six or eight potential answers and you have to tick three or four.
The big marks are on the spelling/punctuation ones, or the written answers.
90% sure there is adjustment for age on the CSSE test.
The CSSE test is not age-standardised. The Chelmsford County High School one is provided by the Durham CEM, and is age-standardised.
As there is a sample English paper on the CSSE website, so the format is freely available to view, I assumed that the OP meant Chelmsford, but I may be wrong!