Linguistic politeness is a whole sub-field of pragmatics (and sociolinguistics). http://en.wikipedia.org/wiki/Politeness_theory gives a fairly good overview of one approach to it. There is lots of stuff out there on it in linguistics.
Linguistic politeness is a whole sub-field of pragmatics (and sociolinguistics). http://en.wikipedia.org/wiki/Politeness_theory gives a fairly good overview of one approach to it. There is lots of stuff out there on it in linguistics.