A Study On Interpersonal Meanings Of Modality In Presidential Inaugural Addresses In The United States (1945-1991)

American presidential inaugural address is a very important variety of political speeches with worldwide influence and long-lasting significance. It has been widely studied from various perspectives, ranging from rhetoric, pragmatics, stylistics, psychology and so on. As there is an increasing consciousness towards the interpersonal aspect of language use (MacCarthy and Carter,1994), this paper sets out to investigate the interpersonal meaning, especially the one realized by modal systems from three functional variables, namely, type, value and orientation within the systemic functional grammar framework. Since it is important to study all the presidential inaugural speeches, this paper focuses on 11 speeches delivered during Cold War (1945-1991).The research shows that the American presidents have distinctive modal choices to highlight their high commitment about the truth of the proposition, establishing themselves as an authority, and at the same time they maintain and establish amiable relationship with the audience. These modal choices not. only coincide with the purpose of presidential inaugural speeches--persuade and motivate hearers to take action in his light, but also correspond to the social background of Cold War (1949-1991), which is a critical period in American history.It is hoped that this paper can serve as a complement to the previous researches of the presidential inaugural speeches. What is more, it is expected to enrich the applications of systemic functional grammar to discourse analysis of interpersonal meanings. Lastly, it may offer insights into the teaching of practical public speaking and improvement of language learners'communicative ability.