This document discusses collocations, which are combinations of two or more words that frequently occur together, like "heavy rain" or "strong coffee". It explains that learning collocations makes language sound more natural to native speakers. Some ways to learn collocations include reading extensively, keeping a record of words that collocate with new vocabulary, and practicing using collocations in context. Finally, it categorizes different types of collocations such as adjective-noun, verb-adverb, and verb-preposition combinations and provides examples.