[3][4] Scholars debate to what extent language mixture can be distinguished from other mechanisms such as code-switching, substrata, or lexical borrowing.
The third model "assumes a gradual loss of the conversational function of language alternation as a means of expressing contrast".
[7] Lexical reorientation, according to Matras, is defined as "the conscious shifting of the linguistic field that is responsible for encoding meaning or conceptual representations away from the language in which linguistic interaction is normally managed, organised, and processed: speakers adopt in a sense one linguistic system to express lexical meaning (or symbols, in the Buhlerian sense of the term) and another to organize the relations among lexical symbols, as well as within sentences, utterances, and interaction.
[8] Pidgins, on the other hand, develop in a situation, usually in the context of trade, where speakers of two (or more) different languages come into contact and need to find some way to communicate with each other.
[9] It also differs from a language that has undergone heavy borrowing, such as Korean, Japanese, and Vietnamese from Chinese (see Sino-Xenic), English from French, or Maltese from Sicilian/Italian.
[11][12] Further, many speakers of Michif are able to identify the French and Cree components of a given sentence, likely from the phonological and morphological features of words.
[12] Scholars propose that, in the Métis multilingual community, Michif emerged as a need to symbolize a new social identity.
[12] The Métis of St. Laurent, a tribe of indigenous people in Canada, were made to feel their language was a sign of inferiority by nuns, priests, and other missionaries who insisted that the Metis switch to Standard Canadian French.
Furthermore, some code-switching and deliberate decisions likely served as mechanisms for the development of Mednyj Aleut and it is possible that these were motivated by a need for a language that reflected the community's new group identity.
These observations, in view of additional language contact cases like Cappadocian Greek, Anglo-Romani, and Mednyj Aleut, suggest that Ma'a arose as a product of massive interference from a Bantu language via intense cultural pressure on a Cushitic-speaking community.
Media Lengua is one of the few widely acknowledged examples of a "bilingual mixed language" in both the conventional and narrow linguistic sense because of its split between roots and suffixes.
[18][19] Such extreme and systematic borrowing is only rarely attested, and Media Lengua is not typically described as a variety of either Quichua or Spanish.
[22] Pieter Muysken suggests that the social context in which the language emerged as an intralanguage involved a presence of "acculturated Indians" that neither identified with traditional, rural Quechua nor with urban Spanish cultures.
The maintenance of Gurindji within the mixed language can be seen as the perpetuation of Aboriginal identity under massive and continuing cultural incursion.
Nonetheless, neither language has an entire grammar and lexicon that is derived from a single historical source and in each case the linguistic group achieves fluent bilingualism.
The social context in which they arose largely distinguishes them from pidgins and creoles and, for some scholars, identifies them closely with mixed languages.
[...] [W]e shall doubtless meet now and then with the claim that such and such a case presents peculiar conditions which separate it from the general class, and that some remote and difficult problem in language-history is to be solved by admitting promiscuous mixture.
Any one advancing such a claim, however, does it at his peril; the burden of proof is upon him to show what the peculiar conditions might have been, and how they should have acted to produce the exceptional result; he will be challenged to bring forward some historically authenticated case of analogous results; and his solution, if not rejected altogether, will be looked upon with doubt and misgiving until he shall have complied with these reasonable requirements.
[36]Wilhelm Schmidt was an important proponent of the idea of mixed languages in the very late 19th and early 20th century.
[38] Margaret Schlauch provides a summary of the various objections to Schmidt's theory of Sprachmischung,[39] by prominent linguists such as Alfredo Trombetti, Antoine Meillet and A. Kholodovich.
Despite these recent efforts to rehabilitate mixed languages as an idea, many linguists remained unconvinced.