@anna Creating a copula is always hard because copulative frames are at the core of how we relate to the world! Maybe this will help: zero linguistic concepts are actual innate facts about language, it's all made up. Even if we acknowledge that it's all transcendent information that helps us navigate the forms of language without knowing things truly, most of it only applies to one language family and starts to fall apart when you look wider. Try to think higher level "how do I want the people who speak this language to organize ideas?" and then pick all the grammar based around that core conceptual model.