The Unsullied are elite warrior-eunuchs bred and trained in Astapor, one of the three major cities of Slaver's Bay. They are slave-soldiers famed for their skills and discipline in battle. They are also often purchased from Astapor by some of the Free Cities, such as Qohor.
The High Valyrian word for a single Unsullied warrior is "Dovaogēdy", while the collective noun referring to "the Unsullied" as a group is "Dovaogēdyr". Given that High Valyrian is an inflected language the endings change depending how it is used in a sentence - i.e. when Daenerys shouts commands at them she says "Dovaogēdys!", because she is using the direct-address form.
From Game of Thrones Wiki: http://gameofthrones.wikia.com/wiki/Unsullied
I think Dovaogēdy is already explained in this sentence, and you can put the translation as an Unsullied. Then, Dovaogēdī (with two macron) is accepting the translation the Unsullied as plural, but not an Unsullied (I think this because it is rejected), and this form is the accusative. For example:
My mom praises the Unsullied.
Ñuha muña Dovaogēdī rijas.
Finally, there is a sentence with Dovaogēdi (with one macron) and you can put the translation as an Unsullied, and this would be the accusative for singular but perhaps the difficult part is that this is also the plural form in nominative.
Edit: I did not copy the last sentence translated as A good woman loves an Unsullied. (and this is how it is translated as accusative), and if you find the same Valyrian for nominative then the verb would have a plural form.
More info about Lunar Noun declensions in the Wiki
Now I think this is something really new for me. We will need to learn this together, and as I can see it is a form called Sixth declesion or Reanalyzed Collectives in HV:
Sometimes a collective acquires so specific a meaning that it begins to be thought of as a separate word (e.g. azantyr "army," originally the collective of azantys "soldier.") At this point, a way to pluralize them becomes necessary, which puts them into the sixth declension. Reanalyzed collectives retain the gender of the original word, and therefore can be any gender.
Note: So I think, it is still necessary to advance more in the HV course to know if this form is used as a singular or plural noun in this language, and perhaps there are more than two numbers (singular and plural) as in other languages. And since my native language is Spanish, I need to say that I do not still understand how all the English collectives work indeed. =)
EDIT: According to the MadLatinist's comment, this would be a regular collective. (the table is also indicating a collective noun, and not named as reanalyzed)
I don't think Dovaogēdyr counts as a reanalyzed collective, it's just a regular collective.
We've only had it once before, when Dany says to Grey Worm Jentys Dovaogēdyro syt iksā "You are the leader of the Unsullied," so it's difficult to say for certain what the difference is, but I think it's something like this: Dovaogēdi "The Unsullied soldiers" vs. Dovaogēdyr "The Unsullied army."
Mi lengua materna también es el español. Acabo de iniciar esta aventura con el Alto Valyrio, también tenía esas dudas con respecto a las diferencias. Me encantaría que estuviese para hablantes en español, así muchísimas personas se unirían.
Aprendo con un lápiz y un papel a la mano, para ir ordenando y estructurando todo el idioma. Tengo un desastre de ingles, español y Alto Valyrio, jajaja, pero se entiende. Pienso lo mismo que tú, entre todos debemos ayudarnos ¡Y también sugerir que esté en español! No sé si existan foros de discusión sobre este tema, si conoces alguno me encantaría saberlo.
¡Hola, saludos! Gracias por tu comentario. Ahora recién veo que también hay una guía en español pero el sitio no está tan completo como en inglés. Es muy bueno tomar notas escritas y crear también algunas planillas con los verbos, sustantivos, etc. (todo ayuda a mejor la memoria para las palabras y frases difíciles).
Aquí hay un enlace con la tabla de verbos de la guía en español. También hay un vocabulario que no está tan completo como en inglés, pero hay una lista de Adjetivos, Adverbios, Sustantivos y Verbos en la parte de Afijos Derivacionales. Espero que sean de gran ayuda. =)
Thanks for your answer Diego! I'm looking forward to learning more and more abotu High Valyrian! That was very informative. I have two questions though. Do we learn more about collectives later in the course (as I'm guessing you finished the tree now)? And how did you make the word "wiki" a link in your post? Thanks!