One of the problems in Engadinese is how to form the possessive.
In modern Romance languages, of course, this is typically accomplished with a preposition derived from Latin DE. The question then becomes, how to do this in Engadinese?
We can’t turn to Modern Greek for help, because the genitive is still alive and well there. And Ray called my first attempt, από, unsatisfactory, instead proposing εκ for TAKE. So that’s one possibility.
But a thought came through my mind: why not look at how other languages do this—specifically, non-Romance languages? And even more specifically, Maltese?
If I recall Bonġornu! Kif int? correctly, the Maltese possessive particle ta’ comes from a construction with an Arabic noun mata‘ or similar, meaning something along the lines of “possession”—so something like il-kiteb ta’ ommi “my mother’s book” comes from something like al-kitāb mata‘ ’ummi “the book, the possession of my mother”.
So perhaps that might be an idea worth following up. Though Greek does not, of course, have the construct state that inspired this construction in Maltese.
But perhaps it’ll lead to something more “organic” than just using εκ.