Language is a very important tool not only for communication, but also for many other factors. One of these factors has a cultural relevance. In ancient times especially, a lot could be said of a people by looking at their language in detail. Firstly, word collocations, or words that frequently appear together, give evidence for what exactly was important for a culture. The Proto-Indo-Europeans, for example, were suggested to have two-part names that were formed from culturally important artefacts. There was also a frequent occurrence of 'fame' in Proto-Indo-European names, illustrating that reputations were important to them. Names are also said to have been passed down from father to son by partially recycling them. Could this be where we got the idea from?
Another interesting idea is the apparent exchanges that took place between the Proto-Indo-Europeans and other tribes. It is very difficult to reconstruct words for 'give' and 'take' for this people, but it is a whole lot easier to find a word for 'exchange' where neither party is considered more important. This is interesting as it sheds light on the possibility of like-for-like trading exchanges where reciprocity is the most fundamental part.
So, what about modern times? Because English has influenced, and been influenced by, so many languages, it has reached across the world. This means that loan words have entered as and when they have been needed. For example, English had no words for 'schadenfreude', 'abseil', 'kindergarten', or even 'hamburger' so we just borrowed them from German. This is a common phenomenon now and something which merely emphasises the Global Village in which we now live.