But WHY does Welsh have mutations? (History & Info)

Maybe you already know that the Welsh language has mutations, and maybe you even know how they work, but WHAT are they really? Why do they exist? Where do they com from? If you already speak Welsh but don't know exactly why you ended up with mutations or if you have only a vague notion that some languages have a thing called "mutations", this video will show how they came about. This is a short history of mutations in Welsh. Go from memorising grammar rules to actually understanding why grammar is the way it is!