Comment Re:Bad idea (Score 4, Insightful) 671
The number of grammatical cases is irrelevant. Question: What's the difference between a grammatical case without stem changes and a postposition (opposite of a preposition? Answer: A space.
That which is challenging, apart from stem changes, is the same thing that is challenging with helper words in general: when to use what with what. Picture a person learning English and trying to remember what to use with what. "I was scolding her.... over it? for it? about it? to it? around it?" "We were unhappy.... over it? for it? about it? to it? around it?" "She was dedicated.... over it? for it? about it? to it? around it?" And so forth. It's the same for people trying to learn which declension case to use in which context. But if the declensions are just suffixes without stem changes, then they're no different from postpositions. And often stem changes where they occur follow pretty predictable rules, often for pronunciation reasons.