If you ever say “kinda” or “sorta”, there’s a good chance you’ve been using ‘Pragmatic Halos’ without even knowing about it. Linguistically speaking, ‘Pragmatic Halos’ can include phrases that are not strictly true (but that are neither lies or mistakes) and which are a normal part of honest, error-free discourse.
“It is a truism that people speak ‘loosely’- that is, that they often say things that we can recognize not to be true, but which come close enough to the truth for practical purposes.”
– explained Professor Peter Nathan Lasersohn (University of Illinois, Dept. of Linguistics) in a 1999 paper for the journal Language, 75 (3): pp.522-551 which carried the first account of ‘Pragmatic Halos’ and their everyday uses.
For a more recent and specific examination of ‘kinda’ and ‘sorta’ – in the Lasersohnian sense, see: Inherent and coerced gradability across categories: manipulating pragmatic halos with sorta, Curt Anderson, Proceedings of SALT 23. (2013)
If, however, you’d like a less colloquial approach, looking at ‘kind of’ and ‘sort of’ instead of ‘kinda’ and ‘sorta’, then see : This is kind of / sort of interesting: variation in hedging in English, Stefan Th. Gries, and Caroline V. David, Towards multimedia in corpus linguistics, 2007