Modality Analysis Of English Purchasing Agreement From The Perspective Of Functional Grammar

Halliday distinguishes three types of meta-functions in language:ideational meta-function, interpersonal meta-function and textual meta-function. Modality, as a subsystem of interpersonal system, plays a significant role in performing the interpersonal function. Up to now, numerous scholars have done studies on the modality system but they mainly focused on how modal operators are realized in different discourses. Only a few studies are concerned with the distribution and realization of modality system in the discourse. Purchasing contract is a legally enforceable document made on the basis of "exchange of goods and services". Quite a lot modal expressions conveying the meaning of obligation, responsibility, permission and command can be found in it.This research, based on the theoretical framework of modality system in Halliday’s systemic functional grammar, selects 22 English purchasing contracts as the data to make further discussion. Qualitative and quantitative studies are carried out, trying to find out how each aspect of modality system, including modal expression, modal type, modal value and modal orientation is realized in purchasing contracts.The research finds that in English purchasing contracts, modality is mainly realized by modal operators, modal adjuncts, expansion of predicators and metaphors of modality. Among the four categories, modal operators are the most preferred, followed by modal adjuncts and expansion of predicators. Metaphors of modality are rarely used. As for the modal type, the percentage of modulation far more exceeds that of modalization. Among the three levels of modal value, high value modal expressions figure prominently. These are mainly adopted to designate mandatory obligation and responsibility. Medium value and low value modal expressions ranks the second and third respectively. As far as orientation is concerned, the modal meaning in purchasing contracts is subjective and implicit. The research findings may be of significance to the writing and interpretation of English business contracts as well as to the teaching and learning of modality system and business contracts.