Prepositions in Natural Languages

If the word can bear its own stress accent, then I would be inclined to write it separately. But if it's a proclitic, you know, it could go either way. It presents interesting problems for especially our manuscripts of Homeric Greek. They were confused all the time about their prepositions. And it sort of keeps editors busy making argumentation for or against. If you have an SOV language, the likelihood that you're going to have post positions is pretty high.