中文摘要：德国哲学家费雷格在1892年提出预设理论，在当时还属于哲学范畴，后来才渐渐被引入语言学领域。经过深入研究发现, 预设分为语义预设和语用预设两种。由于语用预设能够用于把说话者的有深层含义的信息表达出来，相对于语义预设，运用更加广泛。本文选择美国新世纪以来的国情咨文作为研究语料，从预设触发语的角度来分析语用预设在政治话语中的作用。本文采用语料库这一种新兴的手段，分析语用预设触发语中词汇触发语和句法触发语在国情咨文中的分布与频率，总结部分高频触发语的作用。语料库的容量非常大，检索方法也是非常简便。通过分析新世纪以来的国情咨文，笔者发现：动词作为预设触发语能够有效表达总统内心的意图和主张，时间从句作为预设触发语则能影射重大历史事件，引起国会成员的反思。本文旨在加深读者对国情咨文理解，更重要的是，能够提高政治演讲者在写作和演讲中对语用预设的运用能力。

关键词：语用预设；国情咨文；功能；语料库

TABLE OF CONTENTS

中文摘要

ABSTRACT

Chapter One Introduction-1

Chapter Two Political Discourse and Presupposition-2

2.1 Studies on political discourse-2

2.1.1 Definitions of political discourse-2

2.1.2 Introduction to State of the Union Address-3

2.2 Studies on presupposition-3

2.2.1 Philosophical backgrounds of presupposition-3

2.2.2 Semantic presupposition & pragmatic presupposition-4

Chapter Three Research Methodology-6

3.1 Introduction to corpus-6

3.2 Data collection-6

3.3 Research methods-7

Chapter Four Results and Analysis-8

4.1 verbs as presupposition triggers-8

4.1.1 Change of state verbs-9

4.1.2 Factive verbs-10

4.1.3 Iterative verbs-10

4.2 Temporal clause as presupposition trigger-11

4.2.1 As used as presupposition trigger-12

4.2.2 Before used as presupposition trigger-12

4.2.3 After used as presupposition trigger-12

Chapter Five Conclusion-14

5.1 Findings of this thesis-14

5.2 Limitation of this study-15

REFERENCES-16

ACKNOWLEDGEMENTS-17