Question

In what ways did important cultural developments affects spoken language in England between 449 and 1485

Answer 1

It's a long story. In 449, King Vortigern invented "Angle kin" and in 1475 the printing press made its way to Europe. But there's a lot happening between those years.

Here's a Wikipedia article which seems to me to be accurate. But, ya know, don't cite Wikipedia in your paper.
http://en.wikipedia.org/wiki/History_of_the_English_language