* Figurative meaning: Idioms rely on figurative language, which is often more casual and less literal than formal language.
* Cultural understanding: Many idioms are specific to a certain culture or region, making them less universally understood in formal contexts.
* Connotation: Idioms often have a strong emotional or social connotation, which can be inappropriate in formal settings.
Example:
* Formal: "The project was delayed due to unforeseen circumstances."
* Informal: "The project went down the drain because of a big snag."
While you might hear some idioms in formal contexts, it's generally best to avoid them unless you're certain they are appropriate for the audience and setting.
Exceptions:
* Well-established idioms: Some idioms are so widely known and accepted that they are considered part of standard English, even in formal contexts. For example, "to get to the bottom of something."
* Specific professions: Certain professions may have their own set of idioms that are considered acceptable in formal settings, such as in law or medicine.
Overall:
It's always best to err on the side of caution and use clear, direct language in formal contexts. If you're unsure whether an idiom is appropriate, it's best to choose a different phrase.