Most languages have many idioms, which are commonly used phrases or groups of words that are used figuratively, not literally. (Literally means it actually happened – it is not a comparsion. So if you say ‘he literally died’ it means that his heart stopped beating and he is no longer alive.). Idioms get their meaning from the context they are used in. For example, if you say that a famous tennis player “bites the dust” in a tennis tournament, you don’t mean that she literall lies on the ground and eats dirt; you mean she is defeated by another player in that tennis tournament. Idioms can make language more colourful and interesting, but if they are used too often they no longer have that effect as you no longer use your imagination when you hear them. Also, if a writer or speaker uses too many idioms together, they become confusing.
Introduction to idioms