One assumes you already know a bit about Dothraki if you're here, but if not, here's a run-down.
Dothraki is what is termed a "constructed language" or "conlang" -- meaning it is a language that was intentionally and purposefully designed, rather than a langauge which occurred and evolved "naturally."
Dothraki was originally created by George R. R. Martin for use in his novel series A Song of Ice and Fire. Martin conceptualized Dothraki as the native language of the Dothraki people -- a nomadic, warlike culture indigenous to the lands around Eastern Essos in the fictional universe in which A Song of Ice and Fire takes place.
While first used in A Song of Ice and Fire, Dothraki remained no more than a collection of a few hundred words and phrases until the advent of the TV series Game of Thrones in 2011, based on Martin's original series. Directors of the TV series wanted the ability to shoot scenes using dialogue entirely in Dothraki, and so hired linguist David J. Peterson to further develop and flesh out the Dothraki language based on the snippets in Martin's novels and notes. Most of the information available on Dothraki today, and the vast majority of available Dothraki corpora, come from Peterson's published books, blogs, and wikis about the language.
One might wonder, given the fact that Dothraki is not a 'naturally occurring' language spoken natively or fluently by anyone in the world, why someone would bother creating a machine translation system for it. The short answer is: because I thought it was neat.
The long answer is: believe it or not, there exists a small but enthusiastic group committed to learning, using, and expanding the Dothraki language. You can find these brave souls interacting on various web forums, where you might read posts about anything and everything from the minutiae of Dothraki syntax to culturally-bound language philosophy questions such as why there are no words for "murder" or "thank you" in Dothraki. Despite this group of active Dothraki users, I have been unable to find any online translators as of yet which go beyond the simple (and almost entirely incorrect) word-for-word translations you would get by simply thumbing through a dictionary.
To my knowledge, the translation module that functions as the back-end for this site is the only system which attempts to take into account the rich system of inflectional morphology and syntactic complexity that George R. R. Martin and David Peterson have developed for Dothraki. It is thus my hope that this website may be of some limited use to this online community of Dothraki users -- especially as I add in support for more types of syntactic constructions.
It is far from perfect, but it's a start.
Like most conlangs, Dothraki has a relatively small lexicon. While some websites claim the language has up to 3,000 unique lexemes, I have not been able to verify the existence of any Dothraki dictionary or lexeme collection with more than 1,300 or so unique lexical items. In addition to the small size, the Dothraki lexicon is also heavily biased semantically towards warfare, horse-riding, conquest, and other areas of note in Dothraki culture. As you can no doubt imagine, It is thus much easier in Dothraki to talk about killing kings and riding dragons than it is to, say, ask where one has left one's reading glasses.
All of this is really to say that if you're having trouble translating such anachronistic sentences as "My computer crashed after the cello concerto yesterday," this is a feature. Not a bug.
Of course, there are likely more than a few bugs in the system as well, so if you find any, please don't hesitate to email me.
The lexicons used in the translation modules on this site are based on the Dothraki Dictionary created by Richard Littauer. This is the most comprehensive and up-to-date repository of Dothraki vocabulary I have been able to find so far, containing roughly 1,300 entries in all.
Quick disclaimer: the gloss table used for the translator was automatically extracted from a PDF. While I've done some basic entry validation, it's likely more extraction errors lurk in the lexicon of this translator. If you find any, please let me know so that I can correct them.
The morphological and syntactic information included in the translation system on this site comes from David Peterson's excellent Dothraki grammar wiki. While I had initially planned on providing support for all syntactic phenomena outlined in the Wiki before launch, I ultimately decided that throwing the basic translator up on the web now and adding to it over time was preferable to waiting until I had every little detail ironed out. This way at least people might get some use out of it during the development phase.
As of 5/9/2016 the translator modules include support for all inflectional morphology, select derivational morphological operations, and what I felt would be the most commonly used syntactic constructions. At this time constructions like passives, the use of reflexives, noun compounding, and certain clause subordination operations are not currently supported.
The programs which act as the main morphological parsing and syntactic transfer engines in the back-end of the translation modules used on this site were developed by Dr. George V. Wilson. Many thanks are due to Dr. Wilson for his guidance and patience throughout the process of creating this translator.
If you find any bugs, have any suggestions for featurs or vocabulary to add, or just generally want to get in touch, shoot me an email at DothrakiTranslator@gmail.com.
If you're interested, you can find all the source code for the translation system on my github.