The Oxford English Dictionary contains 616,500 words and 10,000 - 20,000 of those are in the average person's vocabulary. Unfortunately, a large percent of those words are only in our recognition vocabularies - not in our everyday speech. Maybe that's why greeting cards are a seven and a half million dollar business. Maybe we're willing to pay $4.99 for a card because we're short on words.
The Miriam Webster Dictionary has more than 100 new words and phrases in its 2007 edition. For example, a sandwich generation is a generation that simultaneously cares for aging parents and growing children. A soul patch is a small spot of beard under a man's lip. Polyamory is the practice of having more than one openly romantic relationship at the same time. Because the English language is constantly growing, dictionary publishers will never get the last word.
The English language is also confusing. An allusion is a direct reference and an illusion is a misconception. Bimonthly is every two months and semimonthly is twice a month. Few is small in number and less is small in amount. Precede means comes before and proceed means move forward. Then there's flammable and inflammable, which mean the same and alright, which doesn't mean anything because it's not a word - all right?
Because our language is confusing, words get mixed up; and we get malapropisms. "A nickel ain't worth a dime anymore", "You can observe a lot by watching", "Ninety percent of the game is half mental" - Yogi Berra is famous for malapropisms. Most men have to try to be as good as their word, but Yogi is better than his.
Puns are phrases that deliberately exploit confusion between similar sounding words for a humorous effect. For example, a Freudian slip is when you say one thing but mean your mother. Or ... a gossip is someone with a sense of rumor. I grew up in a family of punsters. No, I should rephrase that. I survived a childhood of punishment.
People started playing with words in 1913. That's when Arthur Wynne created crossword puzzles. Eleven years later almost every American newspaper had a crossword puzzle. Their popularity led to Scrabble and Sudoku. Fifty million people try to unpuzzle these puzzles every day, making them the most popular word game in the world. Crossword puzzles can't get any more popular than that unless cross words are used in heaven.