"Riña Dovaogēdo muñe rhaenas."
Translation:The girl finds the Unsullied's mother.
First, notice the end of each word:
Riña: (it ends in -a, it indicates is the in the nominative case, in other words the subject of the phrase).
Dovaogēdo (remember, the end -o, indicates is in the genitive case, in other words, is the possesor).
Muñe (ends in -e, it indicates is in acusative, it's the Object Complement of the phrase)(just in case: http://writingexplained.org/grammar-dictionary/object-complement).
Rhaenas (it's a verb, that affect subject).
So you have Subject of the phrase + genitive + object complement + verbs (affecting the subject
Note: Remember that each word has different ends according to their genre.
I hope this helped you. I tried to simplify as much as possible.