The language family also includes Afrikaans, Yiddish, Low Saxon, Luxembourgish, Hunsrik, and Scots.

[5][6] Until the late 20th century, some scholars claimed that all Germanic languages remained mutually intelligible throughout the Migration Period, while others hold that speakers of West Germanic dialects like Old Frankish and speakers of Gothic were already unable to communicate fluently by around the 3rd century AD.

[8] Dialects with the features assigned to the western group formed from Proto-Germanic in the late Jastorf culture (c. 1st century BC).

[44][45] Since at least the early 20th century, a number of morphological, phonological, and lexical archaisms and innovations have been identified as specifically West Germanic.

[49] Today, there is a scientific consensus[50] on what Don Ringe stated in 2012, that "these [phonological and morphological] changes amount to a massive evidence for a valid West Germanic clade".

Even today, the very small number of Migration Period runic inscriptions from the area, many of them illegible, unclear or consisting only of one word, often a name, is insufficient to identify linguistic features specific to the two supposed dialect groups.

Some authors who support the concept of a West Germanic proto-language claim that, not only shared innovations can require the existence of a linguistic clade, but also that there are archaisms that cannot be explained simply as retentions later lost in the North or East, because this assumption can produce contradictions with attested features of the other branches.

The first comprehensive reconstruction of the Proto-West Germanic language was published in 2013 by Wolfram Euler,[55] followed in 2014 by the study of Donald Ringe and Ann Taylor.

By the end of the 6th century, the area in which West Germanic languages were spoken, at least by the upper classes, had tripled compared to the year 400.

[57] It has been argued that, judging by their nearly identical syntax, the West Germanic dialects were closely enough related to have been mutually intelligible up to the 7th century.

The district of Angeln (or Anglia), from which the name English derives, is in the extreme northern part of Germany between the Danish border and the Baltic coast.

The area of the Saxons (parts of today's Schleswig-Holstein and Lower Saxony) lay south of Anglia.

The Angles and Saxons, two Germanic tribes, in combination with a number of other peoples from northern Germany and the Jutland Peninsula, particularly the Jutes, settled in Britain following the end of Roman rule in the island.

The following table shows a list of various linguistic features and their extent among the West Germanic languages, organized roughly from northwest to southeast.

The phonological system of the West Germanic branching as reconstructed is mostly similar to that of Proto-Germanic, with some changes in the categorization and phonetic realization of some phonemes.

Other words, with a variety of origins: Note that some of the shown similarities of Frisian and English vis-à-vis Dutch and German are secondary and not due to a closer relationship between them.