It seems like an odd question, after all language is like air, it's all around and we all need it. We may live in different qualities of language as much as we do of air, but we assume it's just a fabric of life and it is no more necessary to discuss language than it is to equip a bicycle with a fish friendly saddle.
But, our language reveals as much about us as a people as our cloths, food or public monuments. Take English, for example. It's a mish-mash of confusing influences and downright fudging.
Melvyn Bragg presented a very interesting TV show on the history of the English language some time back on ITV (the only reason I will ever watch that moronic channel) and he made a very interesting point, which addressed something that had been bothering me since I was a kid.
Simply put, why is the meat that you get from a cow called beef, that from a sheep called mutton and the poor little piggy gets turned into pork? After when served with the dismembered remains of a waterfowl, it was called duck and chicken was chicken, so why did the farm animals lose their identity going from stable to table?
Well, it was quite simple as he explained. When the Normans arrived in England, they quickly set about stamping out the relatively egalitarian Anglo-Saxon way of doing things and enforced the feudal system on the land. This meant that the previously mostly free-living Anglo-Saxons were now all effectively the property of their lord. All of their produce was his, too and like most kleptocrats they took the best bits for themselves.
Hence the staple meats of the farm ended up on their tables and the peasants were left with the rest. So, while the lowly serf looked after the cow (cu in Old English), the meat was eaten at the table of the French speaking gentry and was called "boeuf" leading to our modern word beef. The sheep gave the lord his dish of "mouton" and the pig was consumed as "porc".
So, when you ask for the roast beef sandwich with the mustard, you are unknowingly acknowledging the mastery of the Normans over the Anglo-Saxons. That's a lot of politics for one meal.