Two organisations write the bulk of UK 11+ papers: GL Assessment and CEM (Centre for Evaluation and Monitoring, originally at Durham University). They test the same subjects but in noticeably different ways, and knowing which one your local school uses changes your study plan considerably.
GL Assessment papers
GL papers are usually delivered as four separate, timed papers — one each for English, Maths, Verbal Reasoning and Non-Verbal Reasoning. The questions are mostly multiple choice, often with five options (A–E). You can practise individual subjects in isolation, which suits many children.
CEM papers
CEM blends subjects within a single paper, so a child might switch from a comprehension passage to numerical reasoning to verbal analogies in the same sitting. The vocabulary range is wider, and timings are tighter. Practice now to see how Quest Arena's mixed mode mimics this pattern.
How to find out which your school uses
Your local council's secondary admissions page usually states the test provider. Independent schools more often write their own papers in an ISEB-style format — closer to GL in structure but with their own quirks.