This document discusses using dictionaries to help language learners understand and use words effectively. It describes different types of dictionaries, including bilingual, monolingual, and learners' dictionaries. Good learners' dictionaries provide information like definitions, pronunciation, examples, collocations, idioms, spelling variations, formality levels, synonyms and antonyms to help students understand words. The document recommends training students to use dictionaries by having them look up words for lessons, find definitions to test each other, and decide which new words to look up.