An idiom is a phrase that means something different from what the words themselves imply, and is meant to be interpreted figuratively. Idioms are expressions you hear in everyday speech or see in writing, though you may not realize it. Expressions like “It’s raining cats and dogs out there,” or “That costs an arm and a leg,” are popular examples in American English. These common expressions are not meant to be understood literally; for example, if it is raining outside, you are much more likely to find raindrops falling than cats or dogs.

Idioms may require some imagination to interpret their meaning. If you are trying to identify an idiom, there is no specific formula you can use to decide if an expression is an idiom or not. However, if you encounter an expression that cannot be understood through a literal interpretation of the words used, it is likely an idiom.

For example, “heart of stone” is a common way to describe someone who acts aloof or unfeeling. Because we know that human body parts are not made of rock, you can infer that the speaker is using a nonliteral expression, or idiom.

Virtually every language has idioms in some form, though individual idioms are often unique to a particular language or culture. When learning a new language, learning the related idioms can help make speech and writing seem more fluent and less formal.

On their own, idioms are not complete sentences, but rather phrases that express a specific idea. Some popular sayings that use idioms include:

  • Break a leg. (A common way to say “good luck” in the theater.)
  • No crying over spilt milk. (Do not get upset over something that has already happened or a small matter.)
  • Don’t count your chickens before they hatch. (Do not count on something that has not happened yet.)
  • Beating around the bush. (Avoiding a topic, not being direct.)
  • The grass is always greener on the other side. (Other situations always seem more appealing than your own.)


"The grass is greener on the other side" is often used as an idiom, meaning other situations seem more appealing than your own. But in this case, the grass is literally greener on the other side (of this fence).


learned behavior of people, including their languages, belief systems, social structures, institutions, and material goods.


way in which an idea is communicated, often by symbols.


based on a figure of speech or metaphor.


word or phrase meant to be understood figuratively.


specific to a particular language or dialect.


set of sounds, gestures, or symbols that allows people to communicate.


having to do with language or speech.


exactly what is said, without exaggeration.