How many words do you need to know?
A summary of ESL Vocabulary Acquisition: Target and Approach by Andreea Cervatiuc, University of
Calgary (Calgary, Canada)
http://iteslj.org/Articles/Cervatiuc-VocabularyAcquisition.html
Scope of article
The article looks at the average receptive
vocabulary size of adult native English speakers,
and asks whether non-native speakers can acquire
a receptive vocabulary of similar size.
Receptive and productive vocabulary
First we must distinguish between receptive and
productive vocabulary. As a rule of thumb, the
receptive vocabulary is at least twice the size of
the productive vocabulary.
How many words do educated native speakers
know (receptive vocabulary)?
The current consensus is somewhere between
13,000 and 20,000 word families, usually around
17,000 word families. (A word family means all
the different parts of speech for one word. So the
words work, working, worked are counted as one
word family, as are economy, economist,
economics, and economic.)
Can non-native speakers achieve this?
This was once thought to be impossible. However,
recent research shows that exceptional adult
second language learners are able to achieve
vocabulary sizes similar to those of educated
native speakers. A recent study (Cervatiuc, 2007)
suggests that the average receptive vocabulary
size of university-educated non-native English
speakers ranges between 13,500 and 20,000 base
words – i.e. similar to educated native speakers.
Research by Milton and Meara (1995) found that
adult learners of English as a second language
could learn 2650 base words per year. The study
involved 53 European exchange students at a
British university. Most students were studying
management science and some were studying
English language and literature teaching.
Word frequency
Research suggests that some words are more
frequent than others and, therefore, more useful
for second language learners. The percentage of
words in a text made up of high frequency words
is shown below.
Top 'x' thousand most frequently
used words
% of words in a
text
2000
3000
4000
5000
79.7
84
86.7
88.6
If you know the 2000 most frequent word families
of English, you can understand approximately
80% of the words in any text. Therefore, the goal
of an English learner should be to acquire these
2000 word families first, since this relatively small
number of words is recycled in any piece of
writing and ensures the basis for reading
comprehension.
An earlier article
(http://www.fltr.ucl.ac.be/fltr/germ/etan/bibs/voca
b/cup.html) on the same topic says:
'Liu Na and Nation (1985) have shown that we
need a vocabulary of about 3000 words which
provides coverage of at least 95% of a text before
we can efficiently learn from context with
unsimplified text. This is a large amount of startup
vocabulary a learner needs, and this just to
comprehend general texts.'
Main conclusion
Acquiring a native-like receptive vocabulary size
in a second language as an adult learner is an
ambitious but achievable goal.
References
If you learned 2650 base words per year, you
would know 17,200 base words in 6.49 years.
The average person may not be able to do this.
The students in the Milton and Meara (1995)
study were top students and exceptional learners,
but it does suggests that building a native-like
vocabulary size in a second language as an adult
learner is an achievable goal.
Cervatiuc, A. (2007). Highly Proficient Adult NonNative English Speakers䴜 Perceptions of their
Second Language Vocabulary Learning Process.
Unpublished PhD Dissertation. Calgary: University of
Calgary.
Liu Na and I.S.P. Nation. 1985. Factors affecting
guessing vocabulary in context. RELC Journal 16, 1:
33-42.
Milton, J., & Meara, P. (1995). How periods abroad
affect vocabulary growth in a foreign language. ITL
Review of Applied Linguistics, 107/108, p. 17-34.