威望高嗰隻變體(簡稱 H)通常會畀人覺得係「高雅」嘅,啲人要寫「正經嘢」嗰陣會用 H 嚟寫;而威望低嗰隻變體(簡稱 L)就成日會畀人覺得「難登大雅之堂」,好多時會畀人誤以為佢係 H 嘅「唔純正版本」,有陣時啲人甚至仲會唔准啲細路用 L 寫嘢,或者淨係准用 L 嚟寫啲「唔正經」嘅嘢[6];不過 L 依然有一定生存空間—實證觀察表明,一個有雙層語言現象嘅群體,日常街坊講嘢會用 L,啲細路通常會用 L 做母語,而且雖然佢哋寫嘢往往會寫 H 唔肯寫 L,但 L 嘅某啲字詞同句法會滲透入去呢個群體所寫嘅 H 嗰度,令到呢個群體寫嘅 H 稍微有異於真係以 H 做母語嘅人所寫嘅[7][8]。雙層語言嘅概念,有助語言學家研究語言演變同埋語言接觸等嘅現象[9]。
德文[歐 10]:德文屬於日耳曼語言,同英文係相對接近嘅「語言親戚」;德文廣泛噉分佈喺中歐多地,包括德國、奧地利、瑞士同埋比利時等多地,都有好多人係用德文嘅;不過事實表明,呢幾笪地方嘅人雖然普遍都識寫標準德文,但一叫佢哋講各自本土語言,佢哋講嘅話往往近乎冇互通能力咁滯;噉係因為德文區亦有雙層語言嘅情況—例如阿勒曼尼話主要分佈喺瑞士同德國南部,呢隻話成日畀人當係「德文」,但隻話同標準德文根本冇互通能力,喺文法等方面亦有明顯嘅差異,同時(至少喺廿世紀嗰陣)學校又成日教阿勒曼尼話嘅使用者要用標準德文寫嘢,就出現雙層語言嘅情況;當中標準德文係 H 而阿勒曼尼話等嘅德文「方言」就係 L [25]。
阿拉伯話:阿拉伯話屬於亞非語系,希伯來話嘅「語言親戚」;事實表明,如果搵分別喺黎巴嫩、埃及同摩洛哥出世同大嘅人,叫佢哋各自噉講佢哋本地嘅「阿拉伯話」,佢哋講嘅嘢會係完全冇互通能力咁滯嘅,而且文法上都有差異,噉係因為呢啲阿拉伯話「方言」雖然同源,但經過咗逾 1,000 年咁耐嘅演變,已經變到冇晒互通能力;不過呢啲地區傳統上都係信回教為主,啲人都會睇用古典阿拉伯文寫嘅可蘭經,令到佢哋有咗一種共同語言—現代標準阿拉伯話[歐 11],簡稱 MSA;啲人屋企人同朋友之間講嘢會用阿拉伯話「方言」,同時學校教嘅係 MSA,好似係公文同學術文等嘅「正經嘢」都傾向係用 MSA 寫嘅,寫阿拉伯話「方言」往往會畀人批評。喺呢種情況下,MSA 係 H 而各阿拉伯話「方言」就係 L [26][27]。
L 消失:啲人嫌自己嘅母語「低級」或者「學嚟都冇用」,所以慢慢開始放棄隻語言,唔肯寫母語,搞到母語唔夠語料用,好多時甚至唔肯教啲仔女講,最後令到 L 走向滅亡。詳情可以睇睇語言滅亡嘅概念;
變成正常嘅多語現象[歐 13]:L 繼續存活落去,做呢個群體嘅人嘅母語,個群體嘅人屋企人同朋友之間繼續用 L,同時個群體嘅人又會或多或少噉學啲 H;喺呢個時候,兩隻語言唔再有 H L 之分—啲人唔再覺得自己母語係「低級啲」另外嗰隻語言「高檔啲」,會容許細路同大人用母語寫嘢,學術文同文學作品等嘅「正經嘢」都可以用母語嚟寫,而如果佢哋要學同用母語以外嘅語言,理由可能係因為想同其他群體嘅人溝通或者為咗興趣學語言呀噉,但並唔會係因為覺得自己嘅母語「難登大雅之堂」或者「唔可以攞嚟做書寫用嘅語言」。
語料:雙層語言嘅其中一個可能影響,係會搞到 L 唔夠語料用—寫低一隻語言有助製造語料,而語料可以幫手紀錄隻語言以及教 AI 處理隻語言,但喺雙層語言嘅狀況下,啲人會覺得 L 唔應該攞嚟寫嘢,往往就會令到隻語言唔夠語料用;例如廿一世紀初嘅粵語就被指有噉嘅情況[29]。
Kyriakou, M. (2019). A critical review of the theory of diglossia: A call to action. International Journal of Linguistics, Literature and Translation (IJLLT), 2(5).
Fellman, J. (1975a). On diglossia. Language Sciences 34, 38-39. "Diglossia for situations of two relatively closely related varieties, and biglossia for circumstances where the varieties in question are varieties of different languages."
Coulmas, F. (1987). What writing can do to language: some preliminary remarks. In
Developments in Linguistics and Semiotics, Language Teaching and Learning, Communication Across Cultures, S. Battestini (ed.), 107-129. Georgetown University Round Table on Languages and Linguistics, 1986. Washington, D.C.: Georgetown University Press,講到雙層語言 "is characterized by a long-term coexistence of native spoken varieties of a language and a written variety which is the mother tongue of nobody."
Keller, R. (1982). Diglossia in German-speaking Switzerland. In Standard Languages: Spoken and Written, W. Haas (ed.), 70-93. Manchester: Manchester University Press,提到「冇人日常街坊講嘢會用 H」係雙層語言嘅重點特徵。
Ferguson, C. (1959). Diglossia. Word, 15(2), 325-340,p. 336 - 原文英譯:"DIGLOSSIA is a relatively stable language situation in which, in addition to the primary dialects of the language (which may include a standard or regional standards), there is a very divergent, highly codified... superposed variety, the vehicle of a large and respected body of written literature, either of an earlier period or in another speech community, which is learned largely by formal education and is used for most written and formal spoken purposes but is not used by any sector of the community for ordinary conversation."
Kyriakou, M. (2019). A critical review of the theory of diglossia: A call to action. International Journal of Linguistics, Literature and Translation (IJLLT), 2(5),呢篇文短啲,得嗰 7 頁紙咁長。
Ferguson, C. (1959): "There is usually a belief that H is somehow more beautiful, more logical, better able to express important thoughts, and the like."
Snow, D. (2013). Revisiting Ferguson's defining cases of diglossia. Journal of Multilingual and Multicultural Development, 34(1), 61-76,有提到 Classical Chinese(文言文)。
Bradley, David (1992), "Chinese as a pluricentric language", in Clyne, Michael G. (ed.), Pluricentric Languages: Differing Norms in Different Nations, Walter de Gruyter, pp. 305-324
Stępkowska, A. (2012). Diglossia: A critical overview of the Swiss example. Studia Linguistica Universitatis Iagellonicae Cracoviensis, (129), 199-209. 3. Swiss German: Low variety with prestige
Palmer, J. (2007). Arabic diglossia: Teaching only the standard variety is a disservice to students. Journal of Second Language Acquisition and Teaching, 14, 111-122.