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]
While the influence of Scandinavian language was strongest in dialects in the Danelaw region and Scotland, the spoken words crept into the language in the tenth and eleventh centuries near the transition from the Old to Middle English period, but such borrowed words only appeared in the Middle English writing at the beginning of the thirteenth century, likely because of a scarcity of literary texts from an earlier date.[6]