Martin & Rose (2007: 21):
Negotiation
The key resources here are for exchanging roles as an interaction unfolds, for example by asking a question and answering it, or demanding a service and complying with the command. Here one speaker demands information with a question, and the other responds with a statement:
Sannie: Are you leaving?
Coetzee: - Of course I'm leaving.
Next a father demands a service with a command, and his son complies:
Hendrik: Ernest, get those snœk [a kind of fish],
Ernest: - (Ernest proceeds to do so.)
Blogger Comments:
Martin's discourse semantic system of negotiation is a rebranding of Halliday's semantic system of speech function. Halliday & Matthiessen (2014: 135):
These two variables [speech rôle and commodity], when taken together, define the four primary speech functions of offer, command, statement and question. These, in turn, are matched by a set of desired responses: accepting an offer, carrying out a command, acknowledging a statement and answering a question.