A for adjectives
Like when you want to say, that the sky is blue, you somehow need to clarify that the “ean” ( = blue / green) belongs to the taw ( = sky). In Na’vi that is done by the little letter A.
=> Taw aean or eana Taw
But why do both Versions work here? The A is something like a little arrow, which points in the direction of the noun it describes.
So it is like that: Ean-a-> Taw or Taw <-a-ean. You can put also put an adjective on both sides of the noun, which should be described. Tsawl-a-> utral <-a-kllvawm, which would mean “The huge brown Tree”. Again, you can see the A as the little arrow which points in the direction of the utral.
If there is an A on both sides of the adjectives you don’t add another A in the direction of the noun. For example the word “apxa”, because apxa + a = apxa but also a + apxa = apxa.
There are also adjectives starting with “le” at the start. If you write that behind the Noun you don’t add an a, only if it is in the front. So “Trr lefpom” but “lefpoma trr”.
The last important thing is that you can’t put two adjectives in front of the Noun, so “Tsawla kllvawma utral” wouldn’t work, because one would have to be on the one side and one on the other “Tsawla utral akllvawm“
A for subordinate clauses
If you want to say something like “The hunter who is running” you kind of want to use a description of the Hunter, like an adjective. And basically, it works like that again.
So to say the sentence “The Hunter who is running” you could say “Taronyu <-a tul” and again, you can see the little arrow pointing into the direction of the noun. And it always works like that. You can even put an entire new sentence behind the a, which would describe the noun at which the A points. Because of the arrow-effect of the A it would also work to put the sub sentence in front of the noun.
“Tul a-> taronyu” would mean the same like “taronyu <-a tul” because of that.
That also works for the case when you want to use more than two adjectives. You can do that with the construction: [Noun] a lu  sì  sì , and so on. Here the sì between the different adjectives is really important. For example like “Syulang a lu hì’i sì lor sì ean”