he latter part of the 11th century was a period of transition from Late Old English to Early Middle English.
The influence of Old Norse certainly helped move English from a synthetic language towards a more analytic or isolating word order, a deep change at the grammatical level.[2][6] The eagerness of Vikings in the Danelaw to communicate with their southern Anglo-Saxon neighbors produced a friction that led to the erosion of the complicated inflectional word-endings;[6][7] Old Norse likely had a greater impact on this deep change to Middle and Modern English than any other language.[8][9][10] Simeon Potter notes: "No less far-reaching was the influence of Scandinavian upon the inflexional endings of English in hastening that wearing away and leveling of grammatical forms which gradually spread from north to south. It was, after all, a salutary influence. The gain was greater than the loss. There was a gain in directness, in clarity, and in strength".[11]
The strength of the Viking influence on Old English appears from the fact that the indispensable elements of the language - pronouns, modals, comparatives, pronominal adverbs (like "hence" and "together"), conjunctions and prepositions - show the most marked Danish influence; the best evidence of Scandinavian influence appears in the extensive word borrowings for, as Jespersen indicates, no texts exist in either Scandinavia or in Northern England from this time to give certain evidence of an influence on syntax. The change to Old English from Old Norse was substantive, pervasive, and of a democratic character.[6][7] Like close cousins, Old Norse and Old English resembled each other, and with some words in common, they roughly understood each other;[7] in time the inflections melted away and the analytic pattern emerged.[9][12] It is most "important to recognise that in many words the English and Scandinavian language differed chiefly in their inflectional elements. The body of the word was so nearly the same in the two languages that only the endings would put obstacles in the way of mutual understanding. In the mixed population which existed in the Danelaw these endings must have led to much confusion, tending gradually to become obscured and finally lost." This blending of peoples and languages happily resulted in "simplifying English grammar."[6]