points for using a specific language

While there is only an IDEA, the essence is this: to award points for using a certain language, for example, if a user writes posts in English, nothing happens, but if he writes posts in Ukrainian, he gets points depending on the amount of text or just for each post. If this is really done, I'm ready to discuss. And also in the opposite direction, i.e. points are deducted for posting in a certain language

We don't have a way to determine what language a post was made in. That's largely impossible without a hefty library for language detection. The best you could do without such a library is award points based off their account language, but that doesn't necessarily mean they posted in that language.