I learned that the antonym of ante is post, both of which were born dual to each other.
If I understand correctly, ob and prae mean the same or related to ante. What are their antonyms? post isn't born dual to them. What words were born dual to them?
("born dual to each other" is strange phrasing. All these prepositions were inherited from Proto-Italic, which inherited them from Proto-Indo-European.)
ante and prae, in their basic meanings, are synonyms, they both mean spatial "in front of, before" and temporal "before". Antonym of both, in these meanings, is post (spatial "behind", temporal "after, since").
ob has different basic meaning: "toward(s), to, in the direction of". Antonym of ob in this meaning is ex / ē.
A rarer meaning of prae is "because of" and this also happens to be a rarer meaning of ob.
