Flexible and abstract: not necessarily
corresponds with political boundaries,
religions or cultures. They are groups
that share at least one language or
variety (job, age, gender...)
General
linguistics
People that share the same
language or dialect in a specific
setting that can be close (city,
neighbourhood, country...)
Does not need to be monolingual
Major types
Diglossic
2 languages or varieties are functionally complementary: formal
and colloquial contexts. Often interwined with bilingualism.
Multilingual
More than 2 official languages, although one is
taken as "official" for practical purposes
Bilingual
Two languages with official status
where there would be monolingual
or bilingual zones
Monolingual
One official language (could be
different dialects, registers or styles)