1 Answer

According to Trudgill 1995: 97-98),

“Diglossia is a particular kind of language standardization where two distinct varieties of a language exist side by side throughout the speech community {…} and where each of the two varieties is assigned a definite social function”.

Charles Ferguson (1959) introduced the term ‘’’diglossia’’’ into sociolinguistics:

“Diglossia is a relatively stable language situation in which, in addition to the primary dialects of the language (which may include a standard or regional standards), there is a very divergent, highly codified (often grammatically more complex) superposed variety, the vehicle of a large and respected body of written literature, either of an earlier period or in another speech community, which is learned largely by formal education and is used for most written and formal spoken purposes but is not used by any sector of the community for ordinary conversation”.(Fasold 1993: 38-39)

http://www.personal.uni-jena.de/~mu65qev/wikolin/index.php?title=Diglossia