One of the most important things to prepare a child for CAT4 testing is to ensure that they are exposed to a wide variety of text documents.
This can be in the form of fiction books, textbooks, instructions, recipes or anything else which may have words.
The more that they read and familiarise themselves with, the more capable they will be of answering comprehension questions. They will also have a wider vocabulary and a deeper understanding of concepts such as spelling.