According to the Global Language Monitor’s (GLM) “English Language WordClock,” there are 1,005,366 words in the English language. The millionth new word (a neologism in lexicographer lingo), “Web 2.0,” entered the 1,400-year-old English lexicon on June 10, 2009 at 10:22 am. The Google/Harvard Study of the Current Number of Words in the English Language also arrived at a similar number — 1,022,000 (a difference of .o121%) — after an analysis of the Google Corpus (more than 200 billion words from American and British datasets mined from books scanned by Google). The Oxford English Dictionaries (OED) comes up with an estimate of 750,000, when counting only distinct senses and excluding variants.
The GLM estimates that in the modern world a new word is created every 98 minutes (approximately 14.7 new words per day). Each year, an estimated 800 to 1,000 neologisms are added to English language dictionaries (in the 20th century alone, more than 90,000 words have been added). Editors of the third edition of the OED, to be completed by 2037, estimate that the rate of inclusion of new words into the OED are about 4,000 per year.
Mark Pagel, an evolutionary biologist at the University of Reading who studies the evolution of language, observes: “What’s interesting about a million is that it’s such a tiny number compared to all the words we could have.” Pagel is right — the English language has the potential to contain more than 100 million words using any combination of seven consonants with two vowels! The Oxford English Dictionary, the most comprehensive dictionary of the English language, contains only 301,100 words, published in 23 volumes in 1989 to 1997 (full entries of 171,476 words and 47,156 obsolete words, and about 9,500 derivative words).
Paul Payack, president of the Global Language Monitor, notes that English is the lingua franca of the modern world: “English has become a universal means of communication; never before have so many people been able to communicate so easily with so many others.” Half a century ago, in 1960, there were approximately 250 million English speakers; today, there are more than 1.53 billion people who speak English as a primary, secondary, or business language.
Fortunately for most English speakers, you do not need to master all million words to converse and write effectively. The average high-school educated English speaker knows about 45,000 words (as high as 60,000 when including proper names and foreign words). David Crystal, a linguist and world-renown expert on the English language, provides these estimates of how many words people know: a person starting school: 500-6,000; a person without a formal education: 35,000; a high-school educated person: 50,000; a college-educated person 50-75,000.
For further reading: The Cambridge Encyclopedia of the English Language by David Crystal, Cambridge (2003)
The Language Instinct by Steven Pinker, William Morrow (1994)