Can't really add anything to those posters who have said more practice and refine that exam technique because he really will need to finish all questions, or as many as he can.
If you haven't got a technique book then I can highly recommend the GL Assessment 11+ Verbal Reasoning Technique Explained available on this site at this linkhttp://www.elevenplusexams.co.uk/shop/9 ... oning.html
If you're a bit of a whiz at VR yourself, then why not go through a paper he's done with him? He can explain his rationale for why he's done a question a certain way and perhaps you can spot a short-cut: encouraging him to spot it himself is best
We did this with Maths and English more than VR, as we were lucky that for the large part, DD2 got it.