Bilingualism vs. Diglossia — What's the Difference?

Using or able to use two languages, especially with equal or nearly equal fluency.

In linguistics, diglossia () is a situation in which two dialects or languages are used (in fairly strict compartmentalization) by a single language community. In addition to the community's everyday or vernacular language variety (labeled "L" or "low" variety), a second, highly codified lect (labeled "H" or "high") is used in certain situations such as literature, formal education, or other specific settings, but not used normally for ordinary conversation.

Using two languages in some proportion in order to facilitate learning by students who have a native proficiency in one language and are acquiring proficiency in the other

The use of two markedly different varieties of a language in different social situations, such as a formal variety at work and an informal variety at home.

Of, relating to, or expressed in two languages

The coexistence in a given population of two closely related native languages or dialects, one of which is regarded as more prestigious than the other; the similar coexistence of two unrelated languages.

A person who uses or is able to use two languages, especially with equal fluency.

(pathology) The presence of a cleft or doubled tongue.

The condition of being bilingual; the ability to speak two languages.

Quality of being bilingual.