Imagine a world in which Scandinavian pirates had never invaded France, forcing the French city of Normandy out from Frankish control, and unto Viking hands. Normandy would never have been invaded by Scandinavians.
One major effect, in fact, the reason I am even considering this scenario, is because the Norman Invasion of 1066 would not have happened (but if it did, it would be directly from Scandinavia, which speaks a Germanic language). This would cause us to still be speaking a relatively Germanic language.
However, there would be other effects, in Britain, and from elsewhere. Today, I want to discuss what differences we would see in this scenario.