The Analysis Of Interpersonal Meaning Of Modality In Public Service Advertisements

The present paper sets out to investigate the interpersonal meaning of modality in public service advertising (PSA) texts based on Halliday's Systemic-functional grammar. 30 authentic public advertising texts are randomly selected from three influential American magazines: Newsweek, Times, and Fortune. According to different benefitors, these samples are divided into three types: PSAs which benefit some particular readers who are addicted to cigarette, alcohol or suffer some diseases; PSAs which benefit both readers and advertisers; and PSAs which benefit the third person apart from readers and advertisers.The study mainly analyzes interpersonal meaning from modal perspectives: modal expression and modal orientation. Firstly, the choice of modal expression is based on types of PSAs. Expression of inclination occurs more frequently in the first type of PSAs to embody a kind of respect for readers'willingness and defend readers'negative faces; expression of obligation mainly appears in the second type of PSAs to emphasize readers'obligation and respensibility for some social event and meanwhile defend advertisers'positive faces; expression of ability turns up more frequently in the third type of PSAs to lay an emphasis on readers'abilities to do some thing and defend readers'positive faces; expression of probability occurs most frequently in all types of PSAs. Expression with different values serves different degree of politeness. Secondly, as for modal orientation, the three types of PSAs have something in common: non-metaphors (implicit subjectivity and implicit objectivity) appear more frequently while modal metaphors (explicit subjectivity and explicit objectivity) occur less frequently in PSAs. The situation mainly depends on the features of PSAs themselves and the feature of every kind of orientation itself, and to some extent different modal orientations serve different degrees of politeness. It is hoped that the findings of this thesis can help readers understand contents of PSAs more accurately and more profoundly, and figure out advertisers'intention and take action in time. In addition, the findings also hope to support a more objective figure of modal expressions with different values for advertisers, enabling them better and more efficiently to persude readers to make an echo based on defending readers'or their own negative or positive faces and it is hoped that the thesis can enrich studies on PSAs.