0 a situation in which there are two different forms of the same language used by a community, used in different social situations -- 双层语言，双言现象（指在特定语言小区里，一种语言存在两种不同变体，各具特定的社会功能）
Diglossia is a type of relationship in which two (or more) languages are used in a complementary distribution of domains.
Such convergence is not surprising when one recalls that diglossia is a case of prolonged contact between two varieties of the same language.
Coulmas questions whether a genetic relationship between languages is a requirement for diglossia.
In diglossia, code alteration is largely of the situational type.
Fishman (1967) refines thinking on diglossia by noting that diglossia could develop with or without widespread bilingualism in a community.
When one or more registers of a language come to be strongly divergent from spoken language, the resulting situation is called diglossia.
The editors not only provide a history of the term but also remind students of the disagreement and confusion about the meaning of diglossia.
Diglossia is associated with another complication.
