2。 The knowledge of idiom

Languages are different from each other，because there are cultural differences．Language, as a part of culture, may reflect the cultural phenomenon of a nation．In a language，vocabulary is endowed with cultural message。 Because the development and changes of a nation’s culture can be found from idioms, and these idioms form very important parts of a language’s vocabulary。

2。1 The definition of idiom

In idiomatic expressions, English vocabulary is rich with the fact that without using idioms it is difficult to speak or write English。 Now, let’s see the definition of idiom。

An idiom (Latin: idiomī, "special property", from Greek: ἰδίωμα – idíōma, "special feature, special phrasing, a peculiarity", f。 Greek: ἴδιος – ídios, "one’s own") is a phrase or a fixed expression that has a figurative, or sometimes literal, meaning。 Categorized as formulaic language, an idiom's figurative meaning is different from the literal meaning(1992。p。495)。 There are thousands of idioms, occurring frequently in all languages。 It is estimated that there are at least twenty-five thousand idiomatic expressions in the English language(1998。p。74)。

Thus knowledge of idioms is an important part of comprehension of the English language。 It is a set expression that has two or more words。 The meaning of the combination cannot be explained in terms of its component parts．In other words, an idiom works as a unit of meaning which cannot be understood from the literal meaning of its member words。 What’s more, an idiom can have the metaphorical meaning , and it may have a much wider application which extends far beyond the literal meaning．