head-final content clause relativizer: it turns the current clause into a subordinate content clause, binds it to the {ke'a} pronoun, and restart the current clause afresh (as if its previous content was erased or moved into a hidden prenex).
Example: «ra na pu klama soi'i ke'a se krinu lo du'u lo snime cu carvi», "they didn't come, because it snowed" (notice how soi'i forcibly closes the scope of the negator na).