Vocabulary is one of the foundations of language learning. Students may understand grammatical rules perfectly, but without sufficient vocabulary they will struggle to understand what they hear or read and to express themselves effectively.

However, knowing a word involves much more than knowing its translation. Learners gradually need to understand its meaning, pronunciation, spelling, grammatical behaviour, collocations and appropriate use in context.

For this reason, vocabulary should not be treated simply as lists of isolated words to memorise. Effective vocabulary teaching involves introducing words in context, creating associations, providing repeated exposure and, most importantly, giving students opportunities to retrieve and use them.

Vocabulary development is also cumulative. As students progress through the levels, they do not simply learn more words: they develop a richer and more precise lexical repertoire, learning synonyms, collocations, phrasal verbs, idiomatic expressions and differences in register.