It is currently well accepted that collocation needs to be taught explicitly. Various experimental research shows that it is one of the most recalcitrant areas in learning L2 languages. Students demonstrate difficulties with it even after achieving a high level of second language competence, contrary to the prevalent assumption that it will be naturally acquired when learners have a certain level of grammatical and lexical competence. This paper suggests one method of teaching collocations with the case of the adjective rich. It demonstrates how the adjective rich extends its meaning and collocates by metaphor, suggesting that teachers` awareness of the cognitive principle of meaning/collocational extension increases students` ability to recognize word combinations in a more flexible way.