Abstract：

American slang is a kind of complicated linguistic phenomenon. The vocabularies and terms of the American slang imply the characteristics of American culture, nationality and society. Many Chinese who learn English may experience such a situation where they cannot fully understand the lines in films or dramas without Chinese subtitles. The main causes can be found out that in American movies or dramas, there are a large number of slang words which we seldom touch upon in our normal English study. The slang words often appear in Americans’ daily conversation and they take up approximately 10 percent of American English in daily use. The Westward Movement taking place in American continent contributed to the formation of American slang, whereas, American slang developed rapidly in the 20th century. The American slang developed its own style and characteristics at that time: humorous, vivid, concise, pithy, rapidly updated and etc. At the same time, its social roles are reflected in several parts: it embodies the reality including the differences of identity, the real life of ordinary people and so on.

Key words: American slang; characteristics; social functions

摘要：

美国俚语是一种复杂的语言现象。美国俚语的词汇与术语暗含着美国文化的特征,美国民族的特性以及美国社会的特点。许多中国的英语学习者也许会有这样的经历：当在观看没有中文字幕的美国电影或美剧时,我们并不能完全听懂电影的语言。究其主要原因,不管是美国电影还是美剧,其剧中语言都有大量的俚语词汇,而我们在常规的英语学习中却很少接触此类词汇。美国人在日常说话中经常出现俚语，俚语的词汇大约占到日常美语的百分之十。19世纪美洲大陆的“西进运动”促使了美国俚语的形成，然而20世纪则是美国俚语迅猛发展的时期。在发展的过程中美国俚语逐渐形成了自己的风格特征：幽默风趣、形象生动、简洁简练、更新迅速等。同时，它在社会中的功能则体现在:它反映了一种现实，包括语言使用者的身份差异，普通民众的真实生活等。

关键词：美国俚语；特征；社会功能

1 Introduction
Academia at home and abroad has different opinions on the definition and classification of slangs. Generally speaking, slang refers to the informal and non-standard English, with its characteristics of popularization, colloquialism and dialect. Webster’s new World College Dictionary defines slang as “highly informal speech that is outside conventional or standard usage and consists both of coined words and phrases and of new or extended meaning attached to established term: slangs develop from the attempt to find fresh and vigorous, colorful, pungent, or humorous expression, and generally either passes into disuse or comes to have a more formal status.’’ (Michael Agnes, 2001:1346) And Cambridge International Dictionary of English defines it as “informal, which might include words and meanings which are not polite and which might stay in use only for a short time. It is used by particular groups of people who know each other, and is usually spoken rather than written.’’(Paul Procter, 1995:1349) People began to use slang in the 16th century, when it appeared in Shakespeare’s works and was regarded as slang at that time, such as ass-head（=blockhead）, fat chuffs（=rich misers）, bawcock（=a fine fellow）and capone（=a love letter）, whose usage was vivid, lively and interesting.