The paper explains the concept of metaphor of mood and metaphor of modality,and then discusses the functions of interpersonal grammatical metaphor in social communications and its special values in discourse analysis.

Halliday points out that language possesses three metafunctions: ideational metafunction, interpersonal metafunction and textual metafunction, and divides Grammatical Metaphor into ideational Grammatical Metaphor and interpersonal Grammatical Metaphor.

Functional linguistics holds that interpersonal metaphors are one of the devices to realize interpersonal meaning.

Metaphors of modality is one of the two types of metaphors included in interpersonal metaphors in systemicfunctional grammar.

This paper starts with a brief introduction of the interpersonal metafunction of the clause in Hallidayan Functional Grammar, and then focuses on the discussion of the two major types of interpersonal metaphors, i.

In this paper,we focus on interpersonal metaphor in two speeches made by the dramatis personae in the novel Invisible Man.

In the construction of discourse,interpersonal metaphor organizes discourse in a way that conforms to the interpersonal intention of discourse by regulating the appropriate assignment of grammatical resources.