Knutti the Viking spoke a language called Old Norse. The Vikings called their language dansk tǫngu ("Danish tongue") or norrænt mál ("Northern speech"). Of course, many of Knutti's customers at his shop in York (Jórvík) were Anglo-Saxons. They spoke Old English.
Mutual intelligibility
Here at The Knutti Store, we're always curious about how the Vikings were able to settle here in Britain. For the Vikings themselves who sought to change their land in the pursuit of a better way of life, the process of change must have been daunting. Yes, they first arrived as raiders and in armies that the English much feared, but as the decades went by, the Vikings increasingly arrived as settlers.
We looked into the question as to whether speakers of Old Norse and Old English could understand each other. We were amazed at what records exist for us to read through and evaluate.
Anglo-Saxon sources
Many stories exist today that were written during the so-called Anglo-Scandinavian period. These include The Voyages of Osthere and Wulfstan and Æthelweard's Chronicles. From these stories we can learn how words that were alien to the English were 'anglicised' and rendered understandable. Our favourite example is the Old Norse word for 'reindeer'. Reindeers didn't and still don't live natively in Britain. The Vikings called them a hreindýri, which was rendered into Old English as hranas (together with an explanation!).
Old Norse sources
In Old Norse, too, there are many stories that have survived. There's The Saga of Gunnlaugr the Serpent Tongue, The Saga of Harald Fair Hair, and The Saga of Harald Hardrada. There is one particular scene in this last example, The Saga of Harald Hardrada, where a local Englishman has an exchange with an invading soldier from Norway. The two men talk freely and unhindered with each other, and there is not a whisper of language difficulty or trouble understanding each other.
And now?
It is thought that some 5% of modern English derives from Old Norse. Today, given the close proximity of the two languages, we're not sure which language, Old English or Old Norse, gave us certain vocabulary.
Curiously, many of the most common words of vocabulary that we use today are the exact same words that the Vikings used when they first arrived in the eighth and ninth centuries. This fantastic article by The Spectator Magazine provides wonderful examples.
And what do we think? Could Knutti understand his English customers?
Happily, we were able to conclude that the Anglo-Saxon customer could understand their Norwegian shopkeeper (Knutti!). This was likely a huge relief for Knutti! Take a look this The Knutti Store publication called The Vikings and the most wonderful English Language and make your own judgment.