A Study On It-extraposition In American Presidential Inaugural Addresses

This thesis,in the light of theories of transformational grammar and systemic-functional grammar,investigates it-extraposition construction in American presidential inaugural addresses from three perspectives:the various forms,the semantic meanings of main clause predicates,and the discourse functions of it-extrapostion.It opts for a corpus-based approach with the corpus of American presidential inaugural addresses and combines the qualitative method and the quantitative method.The conclusions drawn from the thesis are as follows:Firstly,in terms of various forms of it-extraposition,subject it-extraposition is significantly more frequent than object it-extraposition;to-clause is the most common type of extraposed.clauses;the pattern of SPC has the highest frequency among main clause patterns;and adjectival predicates,verbal predicates,nominal predicates and prepositional phrases share different characteristics in distributions.Additionally,the main clause predicates of it-extraposition in American presidential inaugural addresses are inclined to express the meanings of deontic modality and evaluation.To be more specific,obligation,volition and appropriateness are conveyed most frequently.Moreover,there are differences between semantic meanings of main clause predicates of that-clauses and to-clauses.Eventually,with regard to the discourse functions of it-extraposition in American presidential inaugural addresses,experiential function is expressed through modality to present attitudinal meaning;interpersonal function is carried out by questions and provides a certain way of negotiating attitudinal meaning;and textual function is associated with end-focus and end-weight principles.With all aspects considered,the thesis is of significance to the mastering of it-extraposition and the better understanding of American presidential inaugural addresses.It provides valuable references for language teaching,language using and language research.