I think it's time I step in.
Enkien is a language I began developing while designing several hundred Enkis for Ojaveda a couple years ago. At first, it was a simple smattering of a few words to mix into the common tongue in order for them to retain and display pride in their native culture. It has since grown into what it is today, and is still growing. I see nothing wrong with players using this language in-game, as long as other players don't feel ostracized by it (i.e.- using it exclusively in order to separate yourself/group from the rest).
I do come on IRC from time to time and drop a few words or phrases, which tends to cause confusionfor those who don't know and elation for those who know what it is and recognize it. Overuse in-game is very frowned upon, but feel free to sprinkle words/phrases in your RP.
Here are some additions to what's been posted so far:
Mo samoti da rrrive topatendho - I am thankful that here you have arrived anyway. (thankful you are here/have gotten here)
Mo dhorreti ento dhorretolo siino tonphrren - My language and your language are not similar
Ashreto-de - too bad/a shame
Noti venna dhorrhet - you don't know the language I speak
Not'Eso sebhtolo - you're welcome
Joh tiishme? - what is wrong?
Joh tiishmolo? - what is wrong with you?
Dajiil - indeed
Ajha - sure/okay
bonnhetolo - good for you
phonweh - place
jhu phonweh - this place
gwa - why
osghet - quiet
du - so/very
vaatholo - idiot (you)
vaatjho - idiot (general)
osghet - quiet
osghetholo - quiet, you; you be quiet
Taajho - stranger
This is still not everything, but represents 90% of it. Have fun.