How can I encourage my student to widen his vocabulary? 10points and my forever love and admiration!?

What i did was get a student hooked on a book that we read together, then i would read less and less. Eventually he was reading very well and began to see how fun reading could be. As to the vocabulary, its time to show him a thasaurus and perhaps offer a bribe of some sort for every "cool new word" he uses. This is what i did :)