Diglossia

In linguistics, diglossia (/daɪˈɡlɒsiə/; from Koine Greek διγλωσσία from δι- prefix "two" (from δίς, "twice"), γλῶσσα, "language" and -ία, suffix denoting state or attribute, "speaking two languages") refers to a situation in which two dialects or languages are used by a single language community. In addition to the community's everyday or vernacular language variety (labelled "L" or "low" variety), a second, highly codified variety (labelled "H" or "high") is used in certain situations such as literature, formal education, or other specific settings, but not used for ordinary conversation.

The high variety may be an older stage of the same language (e.g., Latin in the early Middle Ages), an unrelated language, or a distinct yet closely related present day dialect (e.g., Standard German with Low German (e.g., Plattdeutsch dialects), or Chinese with Mandarin as the official, literary standard and local varieties of Chinese used in everyday communication). Other examples include literary Katharevousa versus spoken Demotic Greek, literary Tamil versus spoken Tamil and Indonesian, with its Baku and Gaul forms.

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