Languages animate objects by giving them names, making them noticeable when we might not otherwise be aware of them. Tuvan has a word iy (pronounced like the letter e), which indicates the short side of a hill.
I had never noticed that hills had a short side. But once I learned the word, I began to study the contours of hills, trying to identify the iy. It turns out that hills are asymmetrical, never perfectly conical, and indeed one of their sides tends to be steeper and shorter than the others.
If you are riding a horse, carrying firewood, or herding goats on foot, this is a highly salient concept. You never want to mount a hill from the iy side, as it takes more energy to ascend, and an iy descent is more treacherous as well. Once you know about the iy, you see it in every hill and identify it automatically, directing your horse, sheep, or footsteps accordingly.
This is a perfect example of how language adapts to local environment, by packaging knowledge into ecologically relevant bits. Once you know that there is an iy, you don’t really have to be told to notice it or avoid it. You just do. The language has taught you useful information in a covert fashion, without explicit instruction."
— K. David Harrison, The Last Speakers (via containslanguage)