Isogloss in the context of "Benrath line"

A dialect continuum or dialect chain is a series of language varieties spoken across some geographical area such that neighboring varieties are mutually intelligible, but the differences accumulate over distance so that widely separated varieties may not be. This is a typical occurrence with widely spread languages and language families around the world, when these languages did not spread recently. Some prominent examples include the Indo-Aryan languages across large parts of India, varieties of Arabic across north Africa and southwest Asia, the Turkic languages, the varieties of Chinese, and parts of the Romance, Germanic and Slavic families in Europe. Terms used in older literature include dialect area (Leonard Bloomfield) and L-complex (Charles F. Hockett).

Dialect continua typically occur in long-settled agrarian populations, as innovations spread from their various points of origin as waves. In this situation, hierarchical classifications of varieties are impractical. Instead, dialectologists map variation of various language features across a dialect continuum, drawing lines called isoglosses between areas that differ with respect to some feature.

Low German is a West Germanic language spoken mainly in Northern Germany and the northeastern Netherlands. The dialect of Plautdietsch is also spoken in the Russian Mennonite diaspora worldwide. "Low" refers to the altitude of the areas where it is typically spoken.

Low German is most closely related to Frisian and English, with which it forms the North Sea Germanic group of the West Germanic languages. Like Dutch, it has historically been spoken north of the Benrath and Uerdingen isoglosses, while forms of High German (of which Standard German is a standardized example) have historically been spoken south of those lines. Like Frisian, English, Dutch and the North Germanic languages, Low German has not undergone the High German consonant shift, as opposed to Standard High German, which is based on High German dialects. Low German evolved from Old Saxon (Old Low German), which is most closely related to Old Frisian and Old English (Anglo-Saxon).

Standard Macedonian or literary Macedonian (Macedonian: книжевен македонски јазик, romanized: kniževen makedonski jazik or македонски литературен јазик, makedonski literaturen jazik) is the standard variety of the Macedonian language and the official language of North Macedonia used in writing, in formal contexts, and for communication between different dialect areas. Several prestige dialects have developed around the major urban centers of Skopje, Bitola, Veles and Prilep.

It was only in the 1940s, however, that the Macedonian language was able to be implemented, after being formally declared the official language of the Socialist Republic of Macedonia. The rapid pace at which the standardization process took place was in part owing to an already existing interdialect (see spoken Macedonian). The Yugoslav government initially set up a literary Macedonian language based on a spoken dialect of the northern of the Socialist Republic of Macedonia, but it was felt that this dialect was too close to Serbian and finally the dialects spoken in Bitola and Veles were adopted. These dialects, in turn, were closer to the literary Bulgarian, but as the latter was based on the Eastern Bulgarian dialects, it allowed enough differentiation for the Yugoslavs to claim a distinct Macedonian language. Since then, Bulgaria has been contesting the existence of distinct Macedonian language. Thus, the standard variety of Macedonian is phonologically and morphologically based on the central Western Macedonian dialects (in particular, the Prilep-Bitola and Skopje-Veles dialect) with its lexicon influenced by all Macedonian dialects.

Bulgarian dialects are the regional varieties of the Bulgarian language, a South Slavic language. Bulgarian dialectology dates to the 1830s and the pioneering work of Neofit Rilski, Bolgarska gramatika (published 1835 in Kragujevac, Principality of Serbia). Other notable researchers in this field include Marin Drinov, Konstantin Josef Jireček, Lyubomir Miletich, Aleksandar Teodorov-Balan, Stoyko Stoykov.

The dialects of Macedonian are classified as part of Bulgarian in the older literature. Presently, Bulgarian linguistics continue to treat it as such.Since the second half of the 20th century, foreign authors have mostly adopted the convention of treating these in terms of a separate Macedonian language, following the codification of Macedonian as the literary standard language of Yugoslav Macedonia. However, some contemporary linguists still consider Macedonian as a dialect of Bulgarian. Macedonian authors in turn tend to treat all dialects spoken in the geographical region of Macedonia as Macedonian, including those spoken in Bulgarian Macedonia. Together with their closest lexical and grammatical relative they comprise the Eastern South Slavic branch. The present article treats all these dialects together, because of their close structural similarity and the fact that many important dialect boundaries intersect both territories.

Proto-Balto-Slavic (PBS or PBSl) is a reconstructed proto-language descending from Proto-Indo-European (PIE). From Proto-Balto-Slavic, the later Balto-Slavic languages are thought to have developed, composed of the Baltic and Slavic sub-branches, and including modern Latvian, Lithuanian, Polish, Russian and Serbo-Croatian, among others.

Like most other proto-languages, it is not attested by any surviving texts but has been reconstructed using the comparative method. There are several isoglosses that Baltic and Slavic languages share in phonology, morphology and accentology, which represent common innovations from Proto-Indo-European times and can be chronologically arranged.

Pamphylian was a little-attested dialect of Ancient Greek that was spoken in Pamphylia, on the southern coast of Asia Minor. Its origins and relation to other Greek dialects are uncertain, though a number of scholars have proposed isoglosses with Arcadocypriot. It is the sole classical era dialect which did not use articles, suggesting that it split off from other dialects early. Some of its distinctive characteristics reflect potential language contact with Anatolian languages spoken nearby.

Krefeld (/ˈkreɪfɛld, -ɛlt/ KRAY-feld, -⁠felt, German: [ˈkʁeːfɛlt] ; Limburgish: Krieëvel [ˈkʀiə˦vəl]), also spelled Crefeld until 1925 (though the spelling was still being used in British papers throughout the Second World War), is a city in North Rhine-Westphalia, in western Germany. It is located northwest of Düsseldorf, its center lying just a few kilometers to the west of the river Rhine; the borough of Uerdingen is situated directly on the Rhine. Because of its economic past, Krefeld is often referred to as the "Velvet and Silk City". It is accessed by the autobahns A57 (Cologne–Nijmegen) and A44 (Aachen–Düsseldorf–Dortmund–Kassel).

Krefeld's residents now speak Hochdeutsch, or standard German, but the native dialect is a Low Franconian variety, sometimes locally called Krefelder Platt, Krieewelsch Platt, or sometimes simply Platt. The Uerdingen line isogloss, separating general dialectical areas in Germany and neighboring Germanic-speaking countries, runs through and is named after Krefeld's Uerdingen district, originally an independent municipality.

The High German languages (German: hochdeutsche Mundarten, i.e. High German dialects), or simply High German (Hochdeutsch [ˈhoːxˌdɔɪ̯t͡ʃ] ) – not to be confused with Standard High German which is commonly also called "High German" – comprise the varieties of German spoken south of the Benrath and Uerdingen isoglosses, i.e., in central and southern Germany, Austria, Liechtenstein, Switzerland, Luxembourg, and eastern Belgium, as well as in neighbouring portions of France (Alsace and northern Lorraine), Italy (South Tyrol), the Czech Republic (Bohemia), and Poland (Upper Silesia). They are also spoken in diasporas in Romania, Russia, Canada, the United States, Brazil, Argentina, Mexico, Chile, and Namibia.

High German is marked by the High German consonant shift, separating it from Low German (Low Saxon) and Low Franconian (including Dutch) within the continental West Germanic dialect continuum. "Low" and "high" refer to the lowland and highland geographies typically found in the two areas.