Revising lexis: quality or quantity?

This article discusses how much attention language teachers should pay to vocabulary acquisition research, particularly with regard to repeated encounters with lexical items.

Sometime in the middle of the last century, Benjamin Whorf, famous for his contention that language shapes thought, made a controversial statement about the Eskimo language having seven words for snow. Frequently quoted or, rather misquoted overtime, Whorf’s number of snow words was inflated to nine, twenty, fifty, and even one hundred. A similar snowball effect seems to be taking place with the contentious issue of how many exposures a vocabulary item needs for its retention.

About 20 years ago, researchers originally proposed that a second language (L2) learner needs six exposures to a word in order to retain it. However, with the emergence of more and more research into vocabulary acquisition, the number swelled to 10, then 15 and has now reached 20. Do we really need 20 exposures to the word?  How realistic is it? What constitutes an exposure?

How many or how well?
First, my personal experience as a language learner as well as a language teacher shows that you can well do with fewer than six encounters if you have an acute communicative need. For example, if you are desperately groping for a word in L2, and a teacher (or a competent language speaker) supplies it on the spot you are quite likely to remember it. I have learnt many words in French and Spanish exactly this way, by “echoing” what my conversation partner or teacher has said.

Evidently, it is not only “how many times” but also “how well” that should matter. If you come across a lexical item many times but do not do much with it (known as incidental learning), you probably need countless repetitions before it is committed to memory. Conversely, if you are more actively involved in processing the language you meet (known as intentional learning) you are more likely to remember it. It is therefore up to teachers, to create situations and provide meaningful contexts in which learners can have the opportunity to recycle and reuse the language they have learnt.

In or out of context?
Decontextualised language practice was frowned upon during the heyday of Communicative Language Teaching.  However, more and more evidence suggests that decontextualised vocabulary learning is perfectly justified (see for example Laufer, 2006). Students on EAP courses require many academic words such as fundamental, evolution, and welfare to understand dense scientific texts. In order to comprehend them you need to reach a certain level (according to Nation, usually 6000 – 8000 words), and decontextualised rote learning can often be the only way.  However, how can you grasp, let alone use, such expressions as come to think of it or the next thing I know… without meeting them over and over again in meaningful contexts?

Testing the optimal number of encounters is also extremely difficult because there are an infinite number of external factors. One such factor is learnability. Some words are inherently difficult to learn. For example, buy more or less corresponds to the Spanish comprar and should not pose much difficulty for a Spanish-speaking learner of English while many other verbs cannot be mapped onto the same concepts in your first language (L1). For example, pursue does not have a direct word-for-word correspondence with Hebrew. Join can be rendered into French as rejoindre, s'engager, adhérer or devenir membre. It depends on what you want to join in order to choose the right French word, i.e. on the collocations of the verb.

Teaching or researching?
To combat this and other intervening factors researchers often resort to using made-up words (known as “non-words”) in their studies, which I personally have ethical reservations about. Another problem with the studies attempting to count the number of encounters is that they mainly focus on the passive knowledge of vocabulary. For a practitioner teaching Communicative courses where the main aim is so get students to speak and use new language such research is neither valid nor of much use.

When I teach a new lexical chunk in class, I attempt to push the learners’ output as soon as possible by encouraging them to experiment with the new language in different situations. If I were to put my students under experimental conditions, I would have to deliberately stall them while busy counting the number of times a particular chunk was encountered before the learners could produce it.

Individual words versus multi-word items
Most researchers investigating the number of encounters needed to remember new vocabulary unfortunately overlook collocations. It is ironic that the same linguists who strongly propound the importance of learning vocabulary in chunks are preoccupied with counting exposures with individual words.

Establishing how many encounters a learner needs with a new collocation is even trickier What constitutes a new collocation? An intermediate level learner may be:

a) familiar with the words meet and requirement but not know that they can collocate (meet the requirements);
b) familiar with one of the words (reach) in a collocation (reach a compromise)
c) unfamiliar with any of the words (e.g. bear resemblance)

Somewhat paradoxically, evidence suggests that type A collocations may present more difficulty for learners than entirely new collocations (type C). It could be the novelty effect that makes learners pay more attention to new collocations and overlook partially familiar ones, hence frequent errors such as *did a mistake or *made homework.

Furthermore, some research suggests that lexical chunks, which alliterate (e.g. slippery slope, prim and proper), tend to be learnt faster than the ones which do not display such a pattern (see Boers & Lindstromberg 2005).

Coursebooks & schools
Unfortunately, course books do not provide enough encounters with lexical items. Nowadays most course books are organised thematically. While learners may be exposed to the same lexis within a particular unit, few course books ensure the same lexis is recycled across the textbook, i.e. over a series of units. It is therefore the teachers’ responsibility to ensure that the language our students come across is revised in subsequent lessons and regularly recycled.

I once came across an article, which suggested optimum revision intervals as follows:
    10 minutes after the initial encounter
    1 day after the initial encounter
    1 week after the initial encounter
    1 month after the initial encounter
    6 months after the initial encounter

Is it feasible in a school setting? Most EFL classes take place once a week, while in secondary schools there are a lot of timetabling constraints to ensure that the above intervals are adhered to. I would therefore recommend revising new lexis as often as possible whenever an opportunity arises. Teachers can make a good habit of finishing every lesson with a review of the language they have collected on the board during the lesson and starting every new lesson with a quick revision of the language covered earlier on the course.

As regards productive knowledge, the teacher should be able to spot when learners are trying to retrieve a partially learnt item and help them by eliciting it. The teacher may aid the students with prompts and questions or, in other words, provide the necessary scaffolding.

While researchers continue to argue how many encounters with a word are necessary in order for the learner to retain it and what the optimal conditions for retention are, most agree that frequent recycling is essential for effective vocabulary learning. It is our responsibility as teachers to make sure that regular revisiting of the lexis is part of a language course. 


  • Boers, F. & Lindstromberg, S. (2005). Finding ways to make phrase-learning feasible: The mnemonic effect of alliteration. System, 33(2), 225-238
  • Laufer, B.  (2006). Comparing focus on Form and Focus on FormS in second language vocabulary learning. Canadian Modern Language Review 63(1), 149-166
  • Nation, I.S.P. (2001). Learning vocabulary in another language. Cambridge: Cambridge University Press.

By Leo Selivan

This article was first published in September 2010


Submitted by besherry on Wed, 09/15/2010 - 16:05


I can't guess how many encounters are necessary to learn a word, but I think encountering it in different contexts and use scenarios gives you a better chance, it also makes it more likely that you will use the word yourself.

Lexical approach is, i think, one of the finest approach in EFL and it is in line with communicative approach.So quantity is important because students' command and control of vocabulary give the m an edge in communicating.Hence at primary level lexical set is very important help students grasp words in an effective manner.But in an Esl situation quality matters.Herein lies the crux of the problem inherent in every methodology.

 Writing is important in second language teaching where ss need to explain and persuade everything in English.We know every English word is different despite the fact that they are synonyms.Subtle nuances need to be sensed in order to think clearly and express in words.It is said we are to get clear our head out of clutter.A clear sentence is no accident.Clarity and simplicity walk hand in hand as in life and in writing.Writing is hard work.Hence there is need to give our students a practice in right direction to make use of words in context and stylistic use with reference to literature.A good dictionary can be of help,though language acquisition  does not depend on an approach based on an use of a dictionary.In order to quantify several approaches are there including the study of collocations and words used in pairs.So many books in the name of teaching grammar actually teach phrases and idioms.But there is a need to teach the right use of word and a qualitative development toward appropriateness.Hence a logical and clear thinking is needed.And it holds good in an ESL situation.I cannot but quote Ivor Brown who in his introduction to Roget's Thesaurus writes:All who ever took a pen in hand must at some time felt baffled and frustrated.There are several causes for that vexing and distressing condition.A common reason is that the writer has not tidied up his thoughts in advance.

 So i want to say that in ESL situation a little effort should be given and learners need to be pushed an inch ahead every time to clear their head out of clutter and to choose right type of word to express themselves.


Submitted by dcklondon on Fri, 09/17/2010 - 08:31


That lexical chunking is of significance when learning a second language is, of course, not new (see Lewis and the lexical approach of the early 90's).  Much language does consist of pre-fabricated multi-word phrases and teaching collocations, multi-word verbs, binomials, etc... must be part of every lesson.  The key, as the author writes, is "how well" lexical chunking is being introduced.  Usage must be meaningful; students need to see that they can use, and in fact need, these additional chunks of lexis to more accurately describe their world and their lives.  And so, this is why personalisation plays a vital role.  It's sad to find, as a teacher trainer and sometime DoS, that so many teachers still fail to provide students with personally relevant opprtunities to use (and recycle) the language meaningfully, relying instead on course-book provided practice activities that do not "speak" to the students and their experiences.  I echo the author's sentiments that it is the teacher's responsibility to ensure lexis is recycled (and meaningfully), but would also call for course book writers and editors to be more aware of the need to recycle (and re-introduce) lexis across all units of their books.


You and Anup are both spot-on in your observations that I come from the Lexical Approach perspective. I also agree with you that while coursebooks perhaps cannot ensure relevance of the lexical input to ALL learners to an equal measure, but they can easily incorporate more recycling throughout the book.

Very interesting and refreshing: there’s nothing like the sound of informed common sense. So often students get caught between the hard work of arid drills and ‘study’, and the attractive unpredictability of theme-orientated communicative teaching. Finding a middle way – a balance that can harness a principled approach towards lexis and recycling and yet set contexts and trigger meaningful interaction is something that I have been working on for more than I care to remember.   Extended recycling is essential, especially in situations where learners are getting one or two lessons a week and little or no exposure to English outside their classrooms – both in terms of making learning ‘efficient’ (another word frowned upon in the heyday of CLT) and in terms of motivation – learners can see that what they have ‘learnt’ before was worth learning and gain a sense of achievement.

I totally agree with you, recycling language is the key of its successful acquisition. As teachers we very often provide the stds with too much input and little practice. The result is frustration from both parts. I personally do not know if it is 6 times, as many experts say, the minimum exposure to a word to half guarantee that it has been learnt, but what it is sure is that we should work on a more effective way of revising language by means of games, communicative activities etc. rather than constantly teaching new items. This would make stds. more confident when noticing that they can use what they have learnt and it would also give teachers the satisfaction that it is not only a teacher student direction but also student to teacher. In our school we are currently writing activities that foster the use of revising games. I encourage you all teachers to do the same 

Thank you for your comments, Teque and Iain - I am glad you found it refreshing

I don't know if you have seen Jeremy Harmer's recent blog post on the Myth of Multi-tasking. He claims - or rather ponders, among other things, that we can't learn form and meaning at the same time, which provoked a number of interesting comments. I still can't decide where I stand on the issue. I've often felt like you, Teque, that we shouldn't present too much new language without recycling it in a meaningful way in subsequent lessons - and yet my students have sometimes complained that I bombard them with too much new vocabulary. 

Your comment, Iain, seems to back up my position that recycling and opportunities to reuse the new lexis or personalise it (I liked Carmen's example of "debris" above) is essential especially in "one lesson-a-week" contexts. I would go as far as to argue that presenting vocabulary without recycling it does not constitute vocabulary teaching at all but this is perhaps potential material for another article or blog post :)

Submitted by Carmen Rhor on Fri, 09/17/2010 - 20:39


Dear Leo,

I have to agree with you regarding the fact that it actually helps a lot to get to grasp and learn a new word when its meaning can actually express what we exactly want to transmit at the right moment; that is to say, to convey, to click what the context is with the term or expression.

Perhaps it took me only once to learn the word "loo" while I was living in England, my landlady used it and I did not understand its meaning until she made a very clear mimic of what she needed to do "immediately" due to cold weather and the call of nature.

Indeed, it has usually taken me a while to learn idioms, verbal phrases maybe due to the fact that my native language is Spanish, who knows? Or maybe it is entirely up to the kind of intelligence each individual has.

All in all, I am totally convinced that vocabulary is learnt by reading, listening, making sense and above all interest in the learner's motivation.  Sometimes jotting down the pronunciation and later going to the dictionary to find out the equivalence has helped me connect the word with the idea and after a while grasp the meaning of one word.  Just to give you an example of what I am saying, on the exact day of the Twin Towers' attack (September 11th, 2001), I did learn the word "debris"; indeed, I had never come across with that term before, but I shall never forget it in my whole life!

In conclusion, to me learning vocabulary is actually a long-lasting experience and both teacher and student have to work closely in order to implement this skill. It is always a pleasure to use this means of communication to exchange views.

Carmen Rhor (Perú)  

Submitted by huwjarvis on Sat, 09/18/2010 - 15:55


Paul Nation cited in Leo’s references delivers an interesting video webcast lecture on vocabulary size tests and implications for teaching and learning. Check it out from the Keynotes section of    

Submitted by chochole on Sat, 04/16/2011 - 11:22


i am an English teacher of DRC in kinshasa, i have been teaching english as a foreign language for more than ten years. I agree with all that you say, but i think the use of the greetest sensory organs is of great help. I use to practice vocabularies outside the classroom in theatral activities where  poems, plays, songs, dances, defiles created by myself; where vocabularies are practiced by pupils but in a more relax way. How many time a vocabulary should be practised in order to be learnt?  the answer is i do not know but frequent repetitions is the rule. And i can say we never finish to use a word and we never finish understanding it. I think we are just introduced to the new word in the class and it is a live long friendship with it , learning more and more about it  everyday until we die. I think learning a word and understanding it, is a life long experience.

emmanuel bandu DRC  kinshasa

Research and insight

We have hundreds of case studies, research papers, publications and resource books written by researchers and experts in ELT from around the world. 

See our publications, research and insight

Sign up to our newsletters for teachers and teacher educators

We will process your data to send you our newsletter and updates based on your consent. You can unsubscribe at any time by clicking the "unsubscribe" link at the bottom of every email. Read our privacy policy for more information.