http://corpus.byu.edu/coca/THE CORPUS OF CONTEMPORARY AMERICAN ENGLISH(COCA)
450 MILLION WORDS, 1990-2012
The Corpus of Contemporary American English (COCA) is the largestfreely-available corpus of English, and the onlylarge and balanced corpus of American English. The corpus was created byMark Daviesof Brigham Young University,and it is used bytens of thousandsof users every month (linguists, teachers, translators, and otherresearchers).
The corpus contains more than 450million words of text and is equally divided among spoken, fiction, popular magazines,newspapers, and academic texts. It includes 20 million words each year from1990-2012 and thecorpus is also updatedregularly (the most recent texts are fromSummer 2012).Because of its design, it is perhaps the onlycorpus of English that is suitable for looking atcurrent, ongoing changes in thelanguage