"My friend has a dragon."
Translation:Ñuhys raqiros zaldrīzī ēza.
Look for the following noun endings in the possessed nominative noun:
- -ys -os -es -is
- -yssy -ossa -esse -issa
That's the important bit ^ the rest is just explanation and a few notes for where it can be slightly trickier.
... because often (but not always) singular nominative (and vocative) solar nouns end in -ys -os -es -is (there are a few others in subtypes that also end in -s)
... and the plural nominative solar nouns end in -yssy -ossa -esse -issa (the vocative plural is much the same but with an extra -s at the end)
... with the complication for the plurals that the possessive adjective will end in -yz (so ñuhyz) before a vowel or voiced consonant.
(So ... with solar nouns, for the nominative and vocative cases in the singular, and in the plural for the same cases but only before unvoiced consonants.)
All this according to my understanding of the information at the following links:
ñuha is a class 1 adjective: https://wiki.dothraki.org/High_Valyrian_Adjectives#Class_I
The -ys ending is only in the solar nominative and vocative.
Which corresponds with solar nouns from declensions 2 through 4: https://wiki.dothraki.org/High_Valyrian_Noun_Declensions
Careful - in declensions 3 and 5, the accusative has the same form as the nominative (-os -ossa -is -ossa) but the adjective would then need to be ñuhi or ñuhī to be in the accusative case.