Tidbit from Frommer...

[Swoka Swizaw]

Oel karyuti ayoengä polawm about the condition that I am sure some here, as well as myself, have called "ankyloglossia," or tongue-tie; he said this about the difficulty I have with the alveolar trill, "rr":

As for rr, well . . . don't worry about it too much. If you substitute the uvular r as in French, you should be understandable. As a matter of fact, the strongly trilled r that's found in Spanish has different pronunciations in different Spanish-speaking countries. So why not in Na'vi? :-) You can just say you speak a slightly different dialect.

So, it's apparent that he digs the use of other sounds...well, if it makes it easier to render speech, anyway. I know most already knew this, but hey, this was my first email to Frommer. I had to make it personal. (Also, if this is better suited somewhere else more hip, please move it. Thanks.)

[kewnya txamew'itan]

So essentially the Spanish rr is the Omatikayan pronounciation whilst uvular ones may appear in other tribes' accents.

Good to see we've got conformation of something we thought. 

[Swoka Swizaw]

Basically. And it oddly thrills me inside.

[`Eylan Ayfalulukanä]

I wonder if that would also apply to the 'flipped' single r, which I really struggle with.... I eventually got the rolled rr, but with my thick tongue, it sounds more like an engine about to throw a rod!

[kewnya txamew'itan]

For the single r, the tap, the trill could be confusing.

Whatever rhotic (r sound) is used in your native language would probably be fine though.

[Swoka Swizaw]

I wonder if that would also apply to the 'flipped' single r, which I really struggle with.... I eventually got the rolled rr, but with my thick tongue, it sounds more like an engine about to throw a rod!

Perhaps. For me, I'm the opposite. The trill is made by rapidly undulating the tip of the tongue against the alveolar region. Due to my condition, there is no way I can move my tongue that way. In order to do the tap, "r," just jaunt the middle of your tongue against the pallate like with [d]. For me, it just sort of came.

[Kayrìlien]

Whatever rhotic (r sound) is used in your native language would probably be fine though.

Perhaps Bostonians might be an exception to this? 

Kidding aside, basically any "r" sound that isn't just an r-colored vowel is probably acceptable; we'll know what you're trying to say. L and R are notoriously hard sounds for people unfamiliar with them to pronounce, which has (unfortunately) led to many stereotypes, such as Elmer Fudd's heavily de-rhotacized speech, or the mildly racist jokes made about Japanese people pronouncing words such as "English" as "Engrish".

As far as authenticity goes, I would imagine that the closer you can get to sounding like Karyu Pawl, the closer you are to a "true" Na'vi pronunciation. I have to say that listening to the late January audio recording he sent us has been incredibly helpful in trying to nail down the pronunciation.

Kayrìlien