The Song of the Dragonborn features a verse that goes:

Ahrk fin norok paal gran
Fod nust hon zindro zaan

The translation given is:

And the fiercest foes rout
When they hear triumph's shout

Here it implies the suffix "-ro" is used to indicate what would be typical possession for English, 's.  This is the only known instance where this occurs. 

The only existing (canon) words that end in "-ro" are "Feykro", "forest", and "Moro", "glory", so there is some conflict but not much.  If I had to propose an alternate suffix to be used with nouns that end in vowels, it would be "-dro", to make "Feykrodro" or "Morodro".

Thoughts?

paarthurnax

Thoughts?

It's a good idea. And not to overwrite existing rules, the suffix "-ro"/"-dro" can be used for inanimate subjects, while those suffixes from the 4th lesson can be used for animated subjects. (This example - "Consider the sentence, "Zeymahi lost ont du'ul Bormahu", taken from Paarthurnax's dialogue at the end of the main quest." - suits well in this case).

Since the suffixes in the 4th lesson are used to replace "my"/"our"/"their", etc., this woulldn't overwrite those in any way.  In fact you can probably use them in succession: "our father's children", "bormahudro kiir".  Although we might decide as a rule that it is more proper to use one or the other, "un bormahdro kiir" vs. "kiir do bormahu".

paarthurnax

Although we might decide as a rule that it is more proper to use one or the other, "un bormahdro kiir" vs. "kiir do bormahu".

Well, should we? As we use both variants in English. Anyway, the second variant seems to me more formal.