one of the most difficult aspects of learning any foreign language is being able to understand and use a wide range of idioms. the english language has over 15,000 idioms and native speakers use them very frequently, often without realising it themselves. this can make communication with native speakers confusing.
在任何语言学习中最困难的一个方面就是，要能理解并运用大量成语。 英语有15000多个成语，而且本族语使用者常常在不自觉的情况下频繁使用它们。这就造成了与本族语使用者的沟通不畅。
what is an idiom? an idiom is a group of words which, when used together, has a different meaning from the one which the individual words have. for example:
什么是成语呢?一个成语就是一组词，当结合在一起使用时，其意与单个词语所表达的意思均不相同。例如：
-how do you know that sid and nancy have separated
你怎么知道席德和南希分手了?
-i heard it on the grapevine.
我是从小道消息听到的。
of course, the second speaker does not mean he heard the news about john by putting his ear to a grapevine! he is conveying the idea visually of information spreading around a widespread network, similar to a grapevine.
当然，第二个谈话者并不是说，他把耳朵贴在葡萄藤上才听到这个关于约翰的消息的!他只是在形象地表达一种意味，即这个消息通过一个类似葡萄藤的巨大网络传播开来。
we use idioms to express something that other words do not express as clearly or as cleverly. we often use an image or symbol to describe something as clearly as possible and thus make our point as effectively as possible. for example, "in a nutshell" suggests the idea of having all the information contained within very few words. idioms tend to be informal and are best used in spoken rather than written english.
我们使用成语是要表达其它词语无法如此清晰或如此巧妙表达的东西。我们经常会运用比喻和象征以便尽可能清晰地描述事物，因而可以尽可能有效地阐述我们的观点。比如，“in a nutshell”表明的意思是，用很少几个词来涵盖所要表达的全部意思。成语往往是非正式的，最好用于口语，而不要用在非书面表达中。