摘要

    随着中国经济的发展及改革开放的不断深入，中国的国际贸易也取得了巨大的发展。而商务信函作为国际贸易中磋商的必要手段，也越来越受到人们的重视。本文旨在系统功能语法框架下研究商务信函的特点，增强商务信函研究的理论价值。
    本文首先简要介绍了系统功能语法中的人际意义及实现人际功能的相关理论。并以此为理论基础，分析商务信函的人称，语气和情态。结果发现商务信用信函中第一人称和第二人称的使用最为频繁因其有助于在写信人和收信人之间创造一种友好的氛围，缩短二者之间的距离。而情态动词的使用更能够表达写信人的态度和观点。

关键词 商务英语信函，系统功能语法，人际功能，人称，语气和情态

Abstract

With the deepening of reform and opening-up to the outside, the economy of China has been boomed and international trade has made great progress. English business letter being a vital tool in negotiation of international trade attracts more and more people’s eyes. This paper aims at analyzing English Business Letters from the perspective of Systemic Functional Grammar and strengthening the value of the theory used to research on the English Business Letters.
This paper introduces interpersonal meaning and some theory to realize interpersonal function. Then it analyzes the English business letters from the person, mood and modality system. And it turns out that the frequency use of the first pronouns and the second pronouns in English business can help shorten the distance between the writer and the reader and make them more intimate. Modal operators in modality indicate the mood of the letters and can help to express the attitudes of the writer more appropriately

Keywords  English Business Letter, Systemic-Functional Grammar, Interpersonal Function, Person, Mood and Modality

1  Introduction
Since China entered into WTO, China’s economy has been booming and has more connection with foreign countries. A huge number of Chinese companies stepped out of China into Europe, Africa, and other places for their potential markets. In international transactions English has been the most frequently-used language. Communication is indispensable in transactions. However, when people want to negotiate with their foreign partners, they can not communicate face to face each time. Therefore, business letters replace face-to-face communication being a cheap and effective way while people communicate with their foreign partners. So how to write an effective business letter has drawn a lot of researchers’ attention and has been discussed heatedly.