How did old English differ from modern English ?
Old English was the language spoken in what is now England from around the 5th – 11th centuries and is the origin of modern English.
Back then it was called Englisc and the people who spoke were the Anglo-Saxons; Old English is also known as Anglo-Saxon.
Old English is essentially the first recorded version of English and it is the forebear of the language we speak today. Although a modern English speaker would likely have great difficulty in understanding written or spoken Old English, about half the words we use today are derived from Old English.
Who Spoke Old English?
At the beginning of the 5th Century, in what is now England, the local people were speaking Celtic while the government and officialdom spoke Latin, the language of the occupying Roman force.
Britain, however, was coming under increasing attack from raiding parties out of Northern Europe.It was at this point that the Romans left (to defend other parts of the Roman Empire) and the country was essentially undefended.
The raiding parties became more frequent and as they pushed further inland and then began to settle in the country, they pushed the Celtic speakers into the wilds of what is now Wales, Scotland and Ireland.
These raiders and then occupiers were known as Anglo-Saxons. The Angles came from Englalandand spoke Englisc.
The language they used came from back home and it took over completely from Celtic and Latin in much the same way that English settlers several hundred years later settled in North America and Australia bringing their own language with them and just taking a few words from the indigenous peoples and languages.

Writing Old English
Old English was firstly written using Runes. Very few examples survive (only about 200 inscriptions) and they consist mainly of scratched marks on wood, bone or stone.
But then came one of the most important events in the history of English. Towards the end of the 6th Century the Anglo-Saxons converted to Christianity and when this happened the Church arrived and began to write things down on parchment. Often this was done in Latin (the language of the church) but also, significantly, a great deal was done in Anglo-Saxon but in the Roman alphabet.
Following from this, a number of non-Church texts were written or translated and thus we have such Old English masterpieces as Beowulf – an epic poem of over 3000 lines telling the story of the eponymous hero Beowulf who kills the monster Grendel, becomes King, slays a dragon, is fatally wounded, and dies.
It is arguably the greatest piece of vernacular English and certainly one of the earliest.
So by this time Old English was written using an alphabet which is mostly recognizable to today’s reader. However, some letters of that alphabet have been lost. þ = /θ/ as in think ð = /ð/ as in then æ = /æ/ as in hat
Here is an example of Old English from the opening of Beowulf alongside a modern translation. Hwæt! Wé Gárdena in géardagum | Listen! We of the Spear-Danes in the days of yore, | þéodcyninga þrym gefrúnon· | of those clan-kings heard of their glory. |
So although the alphabet is recognizable, along with some words:
Wé = we hú = how
Oft = often hé = he under = under him = him wæs = was cyning = king the language is still very different from modern English due to words we no longer use and a very different grammar.