diglossia to bilingual Fishman (1972a) has generalized the concept of of languages as communities. He notes that a hierarchical evaluation example, in high and low is found in bilingual communities as well. For education domains such as higher Zaire, French is reserved for prestige high language relative law, and administration and thus functions as a presti- to Lingala and other indigenous languages which are used in less of ious domains and thus function like low languages. This extension diglossia to bilingual works in most cases, except that there are many communities in which the high language is also a mother tongue and not necessarily one that is learned only in school