The science behind the vocabulary

The vocabulary of 10,000 words that this website offers was taken from the vocabulary list compiled in 2012 by Paul Nation and Mark Davies, using the "British National Corpus" (BNC) and "The Corpus of Contemporary American English" (COCA).

Paul Nation's BNC-COCA list categorizes words/families of words in different bands or frequency levels: K1, K2, K3, etc. The terminology we’ll use is the following:

  • Level K1 refers to the 1st 1,000 Most Frequent Words of English (words 1 to 1000)
  • Level K2 refers to the 2nd 1,000 Most Frequent Words of English (words 1001 to 2000)
  • ...
  • Level K10 refers to the 10th 1,000 Most Frequent Words of English (words 9001 to 10000)

Notice: In each "K" level, the order of the words was randomized (mixed) so as to provide an even distribution of difficulty for each page of the level.

The BNC/COCA word family lists are available in this website

Discover how many words you still need to learn in each set