Linguists consider Frisian to be the language which is most closely related to English. Today, it is spoken primarily in the Netherlands. There are about 300,000 speakers in Friesland and the West Frisian Islands. The dialect spoken in this area is known as West Frisian. There are also about 10,000 speakers of North Frisian in the German province of Schleswig-Holstein. In addition, there are about 2,000 speakers of Saterland Frisian which is spoken in the German municipality of Saterland. Both Saterland Frisian and North Frisian are considered endangered by linguists.
Looking at the family tree for English and Frisian, both languages stem from Proto-Germanic which is divided into three branches: (1) East Germanic (which includes the now extinct Gothic), (2) North Germanic (which is divided into two groups: (a) Icelandic, Norwegian, and Faeroese, and (b) Danish and Swedish), and (3) West Germanic (which includes Dutch, Flemish, Yiddish, German, Afrikaans, Frisian, and English).
Schleswig-Holstein was once known as Angeln which was the homeland of the Angles who crossed the North Sea to Britain beginning by 449 CE. Here they merged with the Celtic-speaking natives of the island, developed a Celtic-Germanic pidgin which then evolved into the creole which became English.
When two groups of people come into close and regular contact, they frequently develop a pidgin language. Since adults do not have the innate ability to acquire language, this pidgin language will have a simplified grammar and vocabulary. Pidgins are always second languages and they are not fully developed languages.
In the case of the Frisian-Celtic pidgin, the speakers of Old Frisian were men while the speakers of Old Celtic were women. Linguist John McWhorter, in his book Our Magnificent Bastard Tongue: The Untold History of English, reports:
“It turns out that only about 4 percent of British men’s genetic material is traceable to a migration from across the North Sea. Moreover, essentially none of the British women’s genetic material traces back to such a migration, meaning that the invaders were not couples with children, such that women and young’uns would bulk up the total. Rather, the invaders were just a bunch of guys.”When men and women are in close contact, one of the common outcomes is a bunch of children. These children, having the innate ability to acquire and create language, listened to the pidgin language of their parents and developed the creole which would become known as Old English.
Just as Modern English and the Modern Frisian dialects are closely related, Old English is closely related to Old Frisian. In fact, Old English is more closely related to Old Frisian than to Old Saxon. Stephen Oppenheimer, in his book The Origins of the British, points out:
“Old English and Old Frisian both changed their treatment of vowels compared with other Low German languages such as Old Saxon.”In his book The Languages of the World, Kenneth Katzner provides an illustration of Frisian:
“It hat eigenskip, dat de Fryske bydrage ta de Amerikaenske literature tige biskieden is. Der binne einlik mar trije, fjouwer Fryske nammen, dy ‘t yn de Amerikaenske literaire wrâld nei ffoaren komd binne.”English:
“It stands to reason that the Frisian contribution to American literature is a very modest one. There are really only three or found Frisian names that have come to the fore in the American literary world.”