Abstract:

American slang, which is widely used in American daily life, is an informal colloquial variety of English. This paper firstly introduces the definition and significance of American slang, the definition and classification of rhetorical devices and The Big Bang Theory. Secondly, from six aspects, namely, humor and novelty, creating vividness, conciseness and efficiency, expressing emotions, avoiding taboo and conveying cultural connotation, it analyzes the rhetorical features of American slang in The Big Bang Theory. Through concept explanation, literature methodology and case-study, this paper aims to investigate the rhetorical features of American slang, make people know more about the characteristics of American people, cultures and society, and effectively promote cross-cultural communication.

Key words: American slang; rhetorical features; The Big Bang Theory

摘要：

美国俚语是一种使用十分广泛的非正式口语。本文首先介绍了美国俚语的定义和重要性、修辞手法的定义和分类以及美剧《生活大爆炸》，其次从幽默新颖、生动形象、简洁有效、传情达意、避免禁忌和蕴含文化底蕴六个方面分析了《生活大爆炸》中美国俚语的修辞特点。通过定义法、文献查询法以及案例分析法，本文旨在研究美国俚语的修辞特点，加强人们对美国人、美国文化以及美国社会特征的了解，从而有效地促进跨文化交际。

关键词：美国俚语；修辞特点；《生活大爆炸》

1. Introduction
The influence of American English has swept all over the world. As a part of great importance of American English, American slang has been used more frequently. At the beginning, American slang was regarded as informal English and only the underworld would use this variety of English. However, as English evolves, the notion of people has been changed dramatically that the American slang was unaccepted by most Americans. Statistics shows that slang words and expressions account for about ten percent of American vocabulary. The quick development of American slang is paid much more attention by scholars from home and abroad.
In recent years, large numbers of scholars have studied American slang respectively due to their recognition of the importance of American slang. Foreign scholars have studied American slang based on the collection and definitions of American slang and their focus is often on macro-study of American slang through the whole history of the development. Scholars in China, however, have put more emphasis on styles and social functions of American slang. Research has been thoroughly done and the brainchildren are diverse. However few scholars have studied rhetorical features of American slang and paid attention to American slang used in the American sitcom—The Big Bang Theory. So this paper centers on the research of this aspect.