1. How many words do
your students need to
know?
Ron Martinez
University of Oxford
11th Braz-Tesol July 17th, 2008

2. Talk outline
• How many words do experts claim students
need to know?
• Beyond ‘words’, what can make a text
difficult?
• New research evidence
• Implications for language pedagogy (plus an
answer to the question)

3. How many words do native speakers
know?
About 20,000 word families (e.g. Goulden et
al, 1990; Zechmeister et al, 1995)

4. Word ‘families’?
• A word family consists of a headword, its inflected forms,
and its closely derived forms. (Nation, 2001: 8)
• please
• pleased
• pleasing
• pleasure
• pleasant
• pleasurable
• displeasure
• displeased
• unpleasant
• etc...

5. What about language learners?
• 2,000 word families, providing around 80% text
coverage, are enough to study at an English-
language university. (Nation & Hwang, 1995)
• 80% = 1 word in every 5 is unknown.
• 95% text coverage which is the minimum
required for adequate comprehension (Laufer,
1989) and successful guessing from context (Liu &
Nation, 1985).
• For reading to be pleasurable, 98-99% coverage is
desirable. (Hirsh & Nation, 1992)

6. • There is an obvious payoff for learners of
English in concentrating initially on the 2,000
most frequent words, since they have been
repeatedly shown to account for at least 80%
of the running words in any written or spoken
text. (Read, 2004: 148)

7. Is that the whole picture?

8. • This bus is red.
• This bus is green.
• This bus is yellow.

14. Reading is more than words, language
is more than words.
• The principle of idiom is that a language user
has available to him or her a large number of
semi-preconstructed phrases that constitute
single choices, even though they might appear
to be analyzable into segments. (Sinclair
1991:110)

15. The frequency effect
• There is a broad general tendency for frequent words
... to have less of a clear and independent meaning
than less frequent words or senses. These meanings of
frequent words are difficult to identify and explain.
(Sinclair, 1991: 113)
• For example, we think of verbs like see, give, keep, as
having each a basic meaning: we would probably
expect those meanings to be commonest. However,
the database tells us that see is commonest in uses like
I see, you see, give in uses like give a talk and keep in
uses like keep warm. (Sinclair, 1987: vii)

18. • Common words, other than those from the
grammatical closed classes such as pronouns
or prepositions, are common precisely
because they occur in so many expressions.
(Lewis, 1998: 23)

20. Summary
• In L2 reading instruction, vocabulary is gaining in importance,
although both the notion of nuclear vocabulary and the related
notion of teaching the 2,000 most frequent core words for reading
tend to simplify the issues centering on vocabulary development.
(Grabe, 2002: 280)
• …vocabulary lists which consist only of single words risk losing sight
of the fact that many high frequency chunks are more frequent and
more central to communication than even very frequent words.
(O’Keefe, McCarthy & Carter, 2007: 69)
• The overall conclusion regarding the vocabulary of the advanced
level frequency bands must be that, as at the basic level, the single-
word frequency list alone is not sufficient and must be
supplemented by chunks… (O’Keefe, McCarthy & Carter, 2007: 53)

21. Conclusions
• Common words are not ‘easy’.
• 2,000 of the most common words can only provide
80% text coverage if the text contains no collocations
or other multi-word expressions. (Not realistic.)
• Students will often believe that they understand a text
simply because they understand the individual words.
• Proficiency seems to have little effect on the uptake of
collocations in text.
• Current word frequency lists have questionable validity
for informing pedagogical policy and materials
development.

22. References