Abstract

    In international trade, people can exchange information, contact business, discuss trade, negotiate, solve problems and promote friendship through business English letters. The characteristics and functions of business English letters require that people should pay attention to the application of politeness principle in business English letters, so it is necessary to study the application of politeness principle in business English letters.
This thesis includes five parts. The first part briefly introduces the concept of politeness from four aspects: Lakoff’s view of politeness, Leech’s politeness principle, Brown and Levinson’s face theory and positive and negative politeness. The second part introduces lexical features, syntactic features and text features of business English letters. The third part divides business English letters into three types: good-news business English letters, bad-news business English letters and persuasive business English letters. The fourth part states the functions of business English letters. The last part analyzes the application of politeness principle in good-news business English letters, bad-news business English letters and persuasive business English letters.
This thesis helps people to realize the importance of politeness principle in business English letters and flexibly apply politeness principle in business English letters to attain their own business purposes.

Key words: politeness principle; business English letters; application

摘  要

在国际贸易中，通过商务英语信函人们可以交流信息、联系业务、洽谈贸易、磋商、处理问题和促进友谊等。商务英语信函的特点和功能要求人们在商务英语信函中必须注重礼貌原则的应用，故而有必要研究礼貌原则在商务英语信函中的应用。
论文包括五个部分。第一部分从洛克夫的礼貌观、利奇的礼貌观、布朗和莱文森的面子理论及积极的礼貌和消极的礼貌四个方面简要介绍了礼貌的概念。第二部分介绍了商务英语信函的词汇特征、句法特征和语篇特征。第三部分把商务英语信函分成三类：好消息商务英语信函、坏消息商务英语信函和说服性商务英语信函。第四部分阐述了商务英语信函的功能。最后一部分分析了礼貌原则在好坏消息及劝说性商务英语信函中的应用。
论文有助于人们认识到礼貌原则在商务英语信函中的重要性，并在商务英语信函中灵活利用礼貌原则达成自己的商务目的。

关键词：礼貌原则；商务英语信函；应用