The vocabulary a person uses is all the words that person knows and uses. In general, a person who is five knows about 4,000 to 5,000 words.[1]Adults who have gone to college may know 20,000 words.[2] A hearing vocabulary and reading vocabulary are bigger than a speaking vocabulary or writing vocabulary, as people understand some words that they do not use.[source?]
↑Nation, Paul, and Robert Waring. 1997. Vocabulary size, text coverage and word lists. Vocabulary: Description, acquisition and pedagogy, 6-19. [1]
↑Goulden R; Nation P. & Read J. 1990. How large can a receptive vocabulary be? Applied Linguistics11: 341-363.