read read read mantra now ..
He will be sitting for 2017
Though I am not good reader .. so I cant find great books for him to choose
Any help on Authors for him to increase his Vocab
as of now he likes J.K Rowling , David Walliams , Roald dalh
Look on Amazon, search for a book he likes, and they flag underneath a section "people who bought this book also bought...." will have lots of suggestions.
Try Diana Wynne-Jones (the Lives of Christopher Chant, Howl's Moving Castle)
Garth Nix (Monday/Tuesday/Wednesday series)
Skulduggery Pleasant series is good stuff.