In conversation, there are different idioms, phrases, sentence formation (eg.. Maya: how much do you think we need to fund this project? Anil: Well, OFF THE TOP OF MY HEAD, we need at least twenty thousand rupees.) being used. I want the clues and conditions by which we can identify the answers in MCQ type questions.

Dear Student.

An idiom is an expression that has an symbolic meaning. Its meaning is often different from its literal meaning. Every language has idiomatic expressions to stress on a particular idea or information. Some examples of idioms are;

“spill the beans” that means to reveal a secret.

“be an apple of someone's eye” that means to be dear to someone.

“to rest on one's laurels” that means to be satisfied with one's past achievements.

In this way you can identify an idiom.

We hope that this answer solves your query.
Regards.