Dominant Language Constellation is a set of languages that together carry out all the functions of the human language, thus enabling individuals and groups to persist in a multilingual environment . The distinctiveness of Dominant Language Constellation as a set of languages is in that it includes only the most expedient languages, rather than all the languages known to an individual or used in a community, the latter of which characterise language repertoire. Dominant Language Constellation and Language repertoire are complementary concepts. DLC constitutes an active, working part of the pool of language repertoire and typically comprises three languages. A language repertoire, a kind of linguistic resource or storage, may include a much longer list of languages and skills.

DLC applies to both societal language contact and multilingualism and individual multilingual practices. DLC is a pedagogical tool in teacher education.

Vivian Cook (2016, p.10 ):
" DLC is one useful way of looking at multilingualism from a multi-competence perspective".
Li Wei (2020, p. ix):
"With its emphasis on the dynamic and ever-changing nature of multilingualism and the need to embed our analysis and understanding in historical and ideological contexts, DLC makes an original and productive contribution to scholarship and knowledge".
Bernard Spolsky (May 2021, speech at the book launch):
"Particularly important was the application of the theory of DLC to education".