So I wrote "Jon" here and it didn't count it wrong, but it said I have a typo. I can only conclude that this program knows nothing of Jon Snow.
I've found out the difference now! it's not a difference in meaning but depending on what class the adjacent noun belongs to (lunar/solar vs. terrestrial/aquatic). cf. this table: http://wiki.dothraki.org/High_Valyrian_Pronouns#Personal_pronouns