While surfing the net looking for things to write about learning English, I often come across ESL sites that have a 'word of the day' or 'word of the week' box. Some online dictionaries put up free word of the day scripts that you can put on your own site or blog. I did once think about doing it, thinking that it would be a good way for you to improve your vocabulary.
The only problem, however, was that most, if not all, the words that came up were ones that I'd never heard of. This is great for me - as a native English speaker they help me to expand my knowledge of English. But how useful would these words be to a foreign learner of English? Even if you have an extremely advanced level, these words have limited usefulness because no-one ever uses them.
Michael Lewis makes this point in his book 'The Lexical Approach'. He noted that books aimed at proficiency level concentrate on words that even native speakers never use. I have trouble completing the exercises in these books because these words don't figure in my vocabulary. Since when have 'advanced' or 'proficient' been synonyms with 'obscure' or 'useless'?
Having an advanced level in a foreign language doesn't mean knowing a lot of words that even the natives don't know, rather, it means using the same language that the natives use, including slang, idioms and word-plays. And yes, in English that means understanding that awful corrupted, vulgar version of English called 'American'!
I've had hate mail from outraged teachers accusing me of discrediting the profession by teaching things like 'gonna' and 'watcha', but that's another story for another day.