The Interpersonal Metafunction Constructs Social Relationships

Halliday & Matthiessen (1999: 511):

Interpersonally, the grammar is not a theory but a way of doing; it is our construction of social relationships, both those that define society and our own place in it, and those that pertain to the immediate dialogic situation. This constitutes the “interpersonal” metafunction, whereby language constructs our social collective and, thereby, our personal being. The word “construct” is used to suggest a form of enactment — though something on which we inevitably build a theory, of ourself and the various “others” to whom we relate.