How do we know what is being communicated?

Habermas seems to argue that there is one set of rules that can be brought to bear on any communicative action. Yet we know from our own experiences that human communication is hugely complex. Think of an example from your own experiences in the classroom or in a training session: the communications within a formal lesson, in a group discussion, in a lecture theatre with students, or in a meeting. Even within formalised situations there are expected norms of behaviour and (more or less) shared expectations of the teachers' role and pupils' role. These expectations are: largely unspoken, agreed tacitly, sometimes challenged subtly or overtly, bounded within the subtleties of body language, tone of voice, shared or opposing norms and values, and so on.

In addition to these expectations there are a range of other features. Think about how we know what is meant when anyone says something in any given situation? We read complex cues, we make judgements about whether what is said has veracity, we judge whether we trust the other person based on whether we know them or not. Human interaction within any given situation can be a matter of reading signs and making judgements that we often do not make consciously. If this is done consciously, we sometimes cannot reduce to a set of logical propositions why we felt that person A was stating proposition Y in a manner we thought was veridical.