A useful concept for ESL teachers (and learners) is the concept of expressive and receptive vocabulary.
If you have ever learned and used a foreign language, you may have noticed that it is much easier to take in information (listening and reading) than to produce it (speaking and writing). The language that you understand is receptive language and the language that you produce is expressive language.
There may be a lot of words that you recognise, but when it comes to speaking, the words just don’t come to mind. Alternatively, you may get stuck because you lack the repertoire of sentence structures to say what you want to say.
Native speakers, too, use a smaller range of language than they recognise. For example, someone might tend to use the word ‘maybe’ and never use the word ‘perhaps’. Of course, they recognise the word ‘perhaps’ when they hear it.
Native speakers tend to have a smaller difference in the ratio of expressive to receptive vocabulary. ESL speakers tend to have a larger difference. Hence, one goal of a language learner is to become more expressive.
How can you become more expressive? Writing a lot helps, because when you write, you have time to think and you have time to research synonyms for what you wish to say. Another way is to try to use easy synonyms for words that you commonly use. Use ‘perhaps’ instead of ‘maybe’ and ‘for instance’ instead of ‘for example’. Expand your range of emphatic adjectives, so that you say ‘fantastic’ instead of ‘very good’ or ‘awful’ instead of ‘very bad’. (See here for practice on this topic.) Employ active reading and listening techniques so that you are more likely to use what you hear or read.
Finally, this is not too difficult a topic to explain to an ESL class of pre-intermediate and upwards. If they can understand the concept of receptive and expressive vocabulary, it might be a good tool to assist them in their future learning endeavours.
