How many words do I need to know?

One of the questions we are frequently asked is simply how much vocabulary do I need – how many words do I have to learn?

There are many different answers to this depending on who you listen to but the answer is that it’s not necessarily as many as you may think.

The organisation behind the Cambridge English as a Second Language (ESL) exams IELTs – Cambridge University Press and Assessment suggest that:

• To achieve C2 Proficiency (the highest level they recognise), a learner typically needs a vocabulary of around 7,000 to 8,000 “word families”.

• A word family consists of a base word and its derivatives (e.g., help, helpful, unhelpful, helpless, helpfully). This makes sense as knowing the root word like “help” gives you a good chance of understanding derivatives like “helpless” even if you’ve never heard them.

• This means the total number of individual words a C2 speaker knows is certainly higher. However, practical communication at C2 level can often be achieved with around 5,000 frequently used words and perhaps more importantly it enables auto-learning through listening and reading.

The widely recognised Common European Framework of Reference for Languages (CEFR) is less specific and does not specify exact vocabulary sizes for its proficiency levels as CEFR is for all European languages not just English so the number tends to change from language to language and also depends on your native language.

However, various academic studies have attempted to estimate the number of words learners typically know at each level. One such study by Milton and Alexiou (2009) suggests that learners at the

• C2 level may have a vocabulary size ranging from approximately 5,000 to 6,800 words, whereas for

• B2 Upper Intermediate level a smaller 3250 to 3750 is needed.

So there is hope! English learners can be comforted that to achieve C2 proficiency – the gold standard for English ESL exams - may involve knowing around 5,000 to 6,800 word families and practical communication at this level can often be achieved with a smaller subset of frequently used words.