When I first looked into Latin, I saw in a textbook that the dative and ablative singular are the same in the second declension:
And in the plural, the dative and ablative are the same in all declensions.
I thought, "Oh no! These have nearly opposite meanings! I need to keep this ambiguity in mind while hearing/reading a sentence until something resolves it? What if nothing does? How do people live with an ambiguity like that?" Of course I know that English has similar kinds of ambiguity that must be kept in mind, but I still wondered about this. Eventually I learned that a dative noun is never the object of a preposition, which helps.
When reading, I've often been tripped up the dative–ablative ambiguity, but in nearly every case (no pun intended), I've found that only one interpretation was reasonable. Amazing!
So here's my question:
(a) Why is dative–ablative ambiguity not a problem in practice? Or am I mistaken about that: are there actually common, barely noticeable conventions for preventing it?
(b) How do people deal with the ambiguity when it's real? For example, if a ship is named "Deo Data", does that mean "Given by God" or "Given to God"? How do you tell?