Languages do not exist as unconnected entities; rather, every language will be related in some way to every other language…
Systems of measurement might not sound like the most interesting of things, but they can be used to good effect in a role play campaign. There are three main ways I can think of: 1) Adding colour; 2) Culture shock and 3) Archaic systems.
In one region of a forest, all of the trees are identical, down to the leaves and the twigs. If the PCs carve something into one of the trees, it could mystically propigate until it covered all of the trees, or could vanish since it was not carved into the one true tree.