Therefore, it might well be possible to say that the meaning potential of language is determined by context of situation。 In Language, Context and Text, Halliday (1989: 30) proposes the concept of context of situation:

The three features of context of situation is field, tenor and mode。 The field refers to what is happening, to the nature of the social action that is taking place。 The tenor refers to who is taking part, to the nature of the participants, their statuses and roles。 The mode refers to what role the language is playing in the situation, and what are the participants’ purposes by using the language。

 Particularly, the interpersonal meaning can be realized by the tenor of discourse: what kinds of role relationship obtain among the participants, including permanent and temporary relationships of one kind or another, both the types of speech role that they are taking on in the dialogue and the whole cluster of socially significant relationships in which they are involved ( Halliday and Hasan, 1989: 30)。 The concept of context of situation will help explain success and failure in realizing the interpersonal meaning: where a break-down occurs, why it occurs, and how to prevent it from occurring again。 

    Systemic functional linguistics proposes that meaning, sound, and lexico-grammar are three layers of the system。 Although Halliday (1994: 191) discusses other means to realize interpersonal meaning, he mainly holds the view that interpersonal meaning carries a heavy semantic load。 

Recent work has extended the study of interpersonal meaning beyond the clause to the level of discourse。 One major development in interpersonal discourse semantics has been the emergence of Martin and Rose’s Appraisal Theory, included in their book--Working with Discourse: Meaning beyond the Clause (2003)。 There are three different elements of Appraisal Theory, which respectively are attitude, graduation, and engagement。 In terms of attitude, three main types: affect, judgment and appreciation are involved。 Then, force and focus are developed as complementary dimensions of the system of graduation。 As for the engagement, it can be pided into heterogloss and monogloss according to the source of attitudes, introducing a range of additional voices into a discourse via projection (quoting and reporting), modality and concession。论文网

Systemic functional linguistics has been introduced to China for about forty years and great efforts have been made。 Many Chinese scholars try to broaden the framework of interpersonal meaning in systemic functional linguistics and apply it into discourse analysis。   

Based on systemic functional linguistics’ account of modality and interpersonal meaning as well as the language resources discussed in the Appraisal Theory, Li Zhanzi explores the multiple means to achieve interpersonal meaning at the level of discourse, and reestablishes interpersonal meaning from the epistemic, evaluative and interactional aspects in her published essay Broadening the Framework of Interpersonal Meaning in Functional Grammar (2001a)。     

Besides, her paper entitled Interpersonal Meanings of Epistemic Modality in Academic Discourse (2001b) examines epistemic modality in academic discourse and notes that the interpersonal meanings can be multiple, namely, expressing degrees of certainty in cognition, satisfying the politeness principle and negotiating the possibilities of heteroglossia between different stances。

Although Li Zhanzi has already combined Bakhtin’s polyphony and heteroglossia and the concept of intertexuality with interpersonal meaning, Xin Bin is the person who studies the intertextuality in spoken language。 He contributes a lot to the classification of intertextuality by piding it into specific intertextuality and generic intertextuality (2005: 125)。 In A comparative analysis of the specific intertextuality of visiting speeches by Sino-US leaders (2016), he points out that specific intertextuality is an effective communication strategy and psychological tactic in achieving the goal of successful communication and establishing a harmonious interpersonal relationship。 Besides, he also indicates that there is a relationship between quotations and Leech’s “Politeness Principle”。