The English language contains anywhere from 250,000 to a million words, depending on what you consider a word. (I have something of a loose definition of what makes a word and also enjoy floating new ones out to see how far they go, so I'd lean closer to 7 figures than 6.) It is said that the language I'm typing in right now has more words than any other...but how many do we actually put to good use?
The average speaker of American English has a functional vocabulary of well under that. Figures are commonly in the 10,000ish range, but I think even that's something of an overestimation in our dumbed-down modern society where newspapers are written on a 4th grade (-repeating kid's) level and people are deathly afraid of "big words", which is commonly defined as any word with over 2 syllables or 8 letters.
What's more, studies show that the number of words in common use has declined significantly in recent years. (Which I'm sure doesn't come as a shock to anybody who watches a lot of TV...back in the day, even Looney Tunes had some sweet SAT-level vocab. You tell me the last time you heard the word "despicable" without a lisp or heard a cartoon character as eloquent as Bugs Bunny or Foghorn Leghorn.)
For whatever reason, it seems that people would rather overuse the wrong words than learn any more than it takes to pass some standardized test or other. I think that it's an absolutely deplorable state of affairs. It seems that some get used more than others by orders of magnitude, even where inappropriate, and in many cases, that's a damn shame. Maybe the movie "Idiocracy" is coming true. Maybe people just figure they don't need to know all that many words. Maybe it's part of some kind of grand "1984"-y scheme to reduce the number of ways in which people can express themselves and their ideas by gradually phasing words out of everyday use.
It's entirely possible I'm taking this too seriously, but seeing someone use a word incorrectly is like seeing someone play golf with a baseball bat...sure, it's similar enough for people to see what you're trying to do and it might even work on a basic level sometimes, but any enthusiast of the game will be mortified as fuck watching you.
I am such an enthusiast.
There are a lot of words that are answers to the equation overused + often misused = ? (hey, if they can shove letters into math just to confuse me halfway through junior high, I can throw a few words in there) but there are 10 I can immediately think of that get used far too often at the expense of more accurate, descriptive and often more impressive alternatives.