Idioms In English

What is an idiom? 
An idiom, also known as idiomatic expression is a group of words established by usage as having a meaning not deducible from those of the individual words.

Why should English learners use idioms in their informal writing and daily conversation?
Most idioms are informal, so English learners should use them carefully. You will hear or see a lot of idioms used by native speakers in newspapers, magazines, TV shows, films, and songs. Therefore, you will sound more natural and fluent if you use idioms in everyday conversation or informal writing.

How to learn and use idioms accurately
An idiom normally has literal meaning that all words are in strict accordance with their original meanings and figurative meaning that is the metaphorical, idiomatic, or ironic sense of words or expressions. The best way to understand an idiom is to see its context and origin.

The differences among idioms, collocations and proverbs
An idiom is a phrase that has its own meaning that cannot be understood from the meanings of its individual words while a proverb is a short popular saying that impart advice and lessons about how people should behave or that expresses a belief that is generally thought to be true. Idioms are phrases, but proverbs are often clauses or sentences.

A collocation simply means words that often go together such as phrasal verbs: go up, take off and get rid off.