Diglossia

Diglossia is a linguistic situation in which two (often very closely related) languages are used within one speech community, or when a language has two standard forms. This often means that one of the language forms is used as the colloquial language in everyday life, while the other is mainly used in its written form and thereby often has more prestige as well.

A well-known example of a language used in a diglossia situation is Norwegian. It is divided into Bokmål and Nynorsk, the former being more or less archaic and used mainly in formal situations, while the latter is used in everyday life, having been created from local dialects. Arabic too is an example of a diglossic language: it has two standarized forms, one of them being very archaic and only used in writing, in contrast to the vernacular. The difference between these two forms of Arabic is considerable.

Situations of diglossia are especially interesting for sociolinguists, who study the different ways a language is used in diverging situations.