The history of language is the a history of “extinction,” writes John McWhorter at The Atlantic. But there's a contrary trend: “new dialects have been emerging in cities worldwide, and it’s young people—specifically, the children of immigrants—who are driving the trend. One of the surprising consequences of the current wave of mass migration into Europe is, in fact, likely to be the development of ever more new ways of speaking in the future.”

Arabs and Turks who come to Germany, for instance, may learn German, but they don't speak academy German: “In Standard German, ‘Tomorrow I’m going to the movies' is Morgen gehe ich ins Kino— ‘tomorrow go I in the movies.' However, inner-city immigrants’ kids will often say among themselves Morgen ich geh Kino—'tomorrow I go movies'—almost as if they were English-speakers, quietly ironing out that kink in Standard German that forces you to say ‘tomorrow go I' instead of ‘tomorrow I go,' and just saying ‘movies' instead of ‘to the movies.'” The product is “Kiezdeutsch,” a “new dialect” of German. 

McWhorter refers to Black English to indicate that this isn't a Teutonic issue. It's happening everywhere: “dialects like Kiezdeutsch are not a product of conditions specific to Germany. Analogous varieties have emerged in Sweden, Denmark, Norway, and Holland. Specialists call these new versions of old languages in Europe ‘multiethnolects,' but the concept applies equally well outside of Europe. The development of multiethnolects is almost predictable in cities with large immigrant populations. In Senegal, for example, Wolof assigns nouns to eight genders rather unpredictably—and wouldn’t you know, not only migrants to the cities who are not native Wolof-speakers, but also their kids, have a way of using just one of the gender markers for everything.”

This is not the same as pidgin or creole, in which speakers combine “vocabulary from a colonial language” with “grammar from their native languages,” first developing a “makeshift lingo (a pidgin)” and then “a new language entirely (a creole).” Multiethnolects don't develop into separate languages, but enrich the existing dominant language. Yet the immigrants may change the way everyone speaks: “in 50 years there will be gray-haired Europeans of immigrant ancestry using multiethnolect varieties as their casual speech.”