A speech community is a group of people who share a set of linguistic norms and expectations regarding the use of language. The concept is mostly associated with sociolinguistics and anthropological linguistics.
Exactly how to define speech community is debated in the literature. Definitions of speech community tend to involve varying degrees of emphasis on the following:
In linguistics, diglossia (/daɪˈɡlɒsiə/ dy-GLOSS-ee-ə, US also /daɪˈɡlɔːsiə/ dy-GLAW-see-ə) is where 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. The H variety may have no native speakers within the community. In cases of three dialects, the term triglossia is used. When referring to two writing systems coexisting for a single language, the term digraphia is used.
The high variety may be an older stage of the same language (as in medieval Europe, where Latin (H) remained in formal use even as colloquial speech (L) diverged), an unrelated language, or a distinct yet closely related present-day dialect (as in northern India and Pakistan, where Hindustani (L) is used alongside the standard registers of Hindi (H) and Urdu (H); Germany, where Hochdeutsch (H) is used alongside German dialects (L); the Arab world, where Modern Standard Arabic (H) is used alongside other varieties of Arabic (L); and China, where Standard Chinese (H) is used as the official, literary standard and local varieties of Chinese (L) are used in everyday communication); in Dravidian languages, Tamil has the largest diglossia with Literary Tamil (H) used in formal settings and colloquial spoken Tamil (L) used in daily life. Other examples include literary Katharevousa (H) versus spoken Demotic Greek (L); Indonesian, with its bahasa baku (H) and bahasa gaul (L) forms; Standard American English (H) versus African-American Vernacular English or Hawaiian Pidgin (L); and literary (H) versus spoken (L) Welsh.
Prestige in sociolinguistics is the level of regard normally accorded a specific language or dialect within a speech community, relative to other languages or dialects. Prestige varieties are language or dialect families which are generally considered by a society to be the most "correct" or otherwise superior. In many cases, they are the standard form of the language, though there are exceptions, particularly in situations of covert prestige (where a non-standard dialect is highly valued). In addition to dialects and languages, prestige is also applied to smaller linguistic features, such as the pronunciation or usage of words or grammatical constructs, which may not be distinctive enough to constitute a separate dialect. The concept of prestige provides one explanation for the phenomenon of variation in form among speakers of a language or languages.
The presence of prestige dialects is a result of the relationship between the prestige of a group of people and the language that they use. Generally, the language or variety that is regarded as more prestigious in that community is the one used by the more prestigious group. The level of prestige a group has can also influence whether the language that they speak is considered its own language or a dialect (implying that it does not have enough prestige to be considered its own language).
Language shift, also known as language transfer, language replacement or language assimilation, is the process whereby a speech community shifts to a different language, usually over an extended period of time. Often, languages that are perceived to be of higher-status stabilize or spread at the expense of other languages that are perceived—even by their own speakers—to have lower status. An example is the shift from Gaulish to Latin during the time of the Roman Empire.
Language assimilation may operate alongside other aspects of cultural assimilation when different cultures meet and merge.
In the study of language, description or descriptive linguistics is the work of objectively analyzing and describing how language is actually used (or how it was used in the past) by a speech community.
All academic research in linguistics is descriptive; like all other scientific disciplines, it aims to describe reality, without the bias of preconceived ideas about how it ought to be. Modern descriptive linguistics is based on a structural approach to language, as exemplified in the work of Leonard Bloomfield and others. This type of linguistics utilizes different methods in order to describe a language such as basic data collection, and different types of elicitation methods.