These are sometimes explained as o-stem datives in -a < *-ōy, an ending clearly attested in Greek and Indo-Iranian, among others, but there are serious problems with such a view, and the forms are highly coherent, functionally.
這些形式有時解釋為結束於 -a < *-ōy 的 o-詞幹與格，這個結尾明確的證實於希臘語和印度-伊朗語和其他一些語言中，但是這種觀點有一個嚴重問題，這些形式在功能上是高度一致的。