Give an example of an idiomatic expression and explain its usage.

Give an example of an idiomatic expression and explain its usage.

Example of an idiomatic expression: "Break a leg"

Explanation: This idiomatic expression is commonly used to wish someone good luck, especially before a performance or presentation. It is often used in the entertainment industry. The phrase "break a leg" is not meant to be taken literally, but rather as a way to convey encouragement and support. It is believed to have originated from the superstition that wishing someone good luck directly would bring them bad luck, so saying the opposite (i.e., "break a leg") would actually bring them good luck.