I leave out Non-Verbal Reasoning as that directly tests special observational skill - the ability to see subtle patterns and differences.
The lists are short. This is deliberate. I assume that children who are at ease with what is in them, will know more besides.
First Maths. In my book the main requirements are as follows:
1 multiply and divide accurately and from memory up to 12 x 12. Without this, the student will be hard-pressed to perform calculations quickly enough in some of the problem-type questions.
2 do 'longer' multiplication and division efficiently on paper eg. 4 x 27 and 72/4.
Useful practice could be the partitioning method for multiplying, and the bus shelter method for dividing.
3 add, subtract and multiply fractions with the tops and bottoms (numerators and denominators) up to 10. So 1/2 + 3/5; or 3/4 x 2/7
4 simplify fractions using the multiplication tables to divide eg. 4/20 = 1/5
5 convert common fractions such as half, quarter, a third etc into their decimal and percentage equivalents and vice versa. Successful candidates will know, without having to stop and think, that 0.5 is a half - and 25% is a quarter etc.
6 convert the basic metric measures: mm to cm; cm to m; and m to km. Likewise for weights: g and kg; and capacity: ml and l.
And an overall tip: Recognise that the Kent Test does not reward Mental Arithmetic. Therefore, be in the habit of using pen and paper for working things out.
And now the requisites of English and Verbal Reasoning:
1 appreciate how capital letters, full stops, commas and question marks are employed in standard written English, and apply them in writing
2 appreciate and apply the basic spelling principles such as: cane -> caning,
can -> canning, story -> stories
3 have a feel for language as a system, including basic parts of speech (nouns, verbs, adjectives and adverbs) - singular and plural - tenses, past, present and future.
4 have an interest generally in words, phrases and meanings, and enjoy puzzles such as word searches and anagrams.
And above all, read questions and instructions attentively, and answer them to the letter - an English skill that must be applied across all Tests!