Classroom communication is best characterised as a social activity where interpersonal relationships are created, maintained and even changed through teacher-student interactions. A close analysis of some of the discourse features suggests that what differentiates the way teachers interact with 'more successful' and 'less successful' students is the extent to which they focus on 'task talk' and 'procedural talk'. Because these modes of talk sometimes function metacommunicatively, any switching between these modes can potentially trigger the operation of a mutually reinforcing circle, with 'labelling' and 'patterns of interaction' working on each other.