Abstract
This paper selects 10 typical examples of political speeches made by President Obama as the corpora. Statistic analyses are emphasized on two of them, and the rest are for reference. The thesis picks out hedges, calculates the frequency and distribution of the hedges among the predominant three examples, which are analyzed under the pragmatic theories of the Cooperative Principle, the Politeness Principle and the Face Threatening Theory, etc. It explores the pragmatic functions of hedges in Obama’s speeches. The research aims to enlighten people like statesmen or speakers. Additionally, it benefits English teaching, which offers Chinese students a better understanding of hedges and application to communicative skills
Keywords   political speeches   hedges   pragmatic functions  
 
 本研究选取美国总统奥巴马的十篇具有代表性的演说为语料依据自建小型语料库，以三篇作着重数据分析，其余语料作参考，挑出符合模糊修饰语（也有学者翻译为模糊限制语）的表达，统计模糊限制语出现的频率以及各类模糊限制语的分布状况。以合作原则，礼貌原则及面子威胁论等语用原则为理论基础对数据进行分析，研究模糊限制语的语用功能在政治演讲中的体现方式。通过此研究，希望对演说者恰当使用模糊限制语提高表达效果有所启发；此外，奥巴马的演讲素材有助于英语教学，提高中国学生对模糊限制语的了解，并运用于交际技巧。
关键词  政治演说   模糊限制语   语用功能

Fuzziness is one of the fundamental features of language，and it prevails in language. It is not taken as a theory until L.A Zadeh, an American mathematician, raised the fuzzy set story in 1965. “All the language is more or less fuzzy”.. WuTiePing states that “fuzzy language has become an indispensible part in everyday communication and that human language would be unnatural without fuzzy language”. Since hedges are a core member in fuzzy language, it occurs frequently in daily communication. George Lakeoff introduced “hedges” in his paper “Hedges: a study in meaning criteria and the logic of fuzzy concepts”.