In the world of grammarians there are two competing camps:
descriptivists
and
prescriptivists.
Edward Finegan of the University of Southern California sums up the
difference:
Descriptive grammarians ask the question, “What is English (or another
language) like – what are its forms and how do they function in
various situations?” By contrast, prescriptive grammarians ask “What
should English be like – what forms should people use and what
functions should they serve?”
In the prescriptivist camp falls Lynne
Truss, The “blog” of “unnecessary”
quotation marks, and your high
school English teacher. Prescriptivists aim to help us use the English
language properly. The intention is noble: if we all speak the same
language, we can communicate much more effectively. But it’s a bit
Quixotic: if language was static, we’d all still write like Chaucer.