2.3.1 - Vowel Contraction
Since identical vowels may not occur next to each other, a few grammatical processes involve a doubled vowel reducing to just one.
2.3.1.1
The adjective morpheme -a- disappears when attached to an a at the start or end of an adjective, as in apxa tute not *apxaa tute.
2.3.1.2
When the dual and trial prefixes leave a sequence of two es, as in me + ’eveng > *meeveng (note lenition), the two vowels contract to just one, meveng.
2.3.1.3
When the prenoun prefixes end in the same vowel the following word starts with, they reduce to one, as in tsatan < tsa- + atan, fìlva < fì- + ìlva (3.3.6). Note: the glottal stop is a consonant, so fì'ìheyu from fì- + 'iheyu.
2.3.1.4
Contraction does not occur for indefinite -o or enclitic adpositions. When two identical vowels occur next to each other, they are written with a hyphen between them, fya’o-o "some way", zekwä-äo "under a finger". Note: Though Forest Na'vi does not technically have long vowels, the effect of long vowels occurs in this situation. Take care to pronounce both ä in a word such as zekwä-äo.
2.3.1.5
In Reef Na'vi vowel contraction is not applied. Forms such as meeveng or apxaa remain, where Forest Na'vi would simplify the doubled vowels.
2.3.2 - Pseudovowel Contraction
Due to the shape of the aspect infixes, ‹er› and ‹ol›, it is possible for the pseudovowels to occur immediately after their consonantal counterpart, as in *p‹ol›lltxe. When this happens in an unstressed syllable, the pseudovowel disappears, poltxe. In a stressed syllable, the infix disappears, *f‹er›rrfen > frrfen. Pseudovowels in monosyllables behave as though unaccented, vol from *v‹ol›ll, and ner from *n‹er›rr. [1]
2.3.3 - Affect Infix Epenthesis
When the positive affect infix ‹ei› is followed by the vowel i, ì or a pseudovowel, a y is inserted, seiyi < *s‹ei›i, veykrreiyìn < *veykrr‹ei›ìn; v‹ei›yll < *veill. [1]
2.3.3.1
The dissimilation of seii into seiyi does not occur in Reef Na'vi.
2.3.4 - Reef Na'vi Voiced Stop Assimilation
In Reef Na'vi, when a word has a cluster of ejectives, such as in atxkxe land, regressive voicing assimilation takes place. That is, the onset voiced stop (*atxge) causes the voicing of the previous coda ejective as well, giving, adge. Similarly, ekxtxu rough is egdu in Reef Na'vi.
2.3.5 - Nasal Assimilation
In many compounds as well as in some idioms, final nasals assimilate to the position of the following word, as in lumpe as a variant of pelun. Such assimilation is not always written, which may make the etymology of a word clearer, as in zenke instead of *zengke, from zene ke, or in the several idioms with the verb tìng give, tìng mikyun being pronounced tìm mikyun.
2.3.6 - Vowel Harmony
Na’vi has two instances of optional regressive vowel harmony in verb infixes.
2.3.6.1
The subjunctive future infix, ‹iyev›, most frequently appears as ‹ìyev›, with backing of the first vowel.
2.3.6.2
The vowel of the negative attitude infix, ‹äng›, may be raised if it is immediately followed by the vowel i, becoming ‹eng›, as in tsap’alute sengi oe I apologize.
2.3.7 - Elision
In rapid speech final -e is frequently elided when the following word starts in a vowel. Kìyevame ulte Eywa ngahu. This is not indicated in writing. When the final -e is in a monosyllable (ke, sre), or when it is stressed (tuté), it is not elided.
2.3.7.1
The vowel ì in mì, sì and the adverb prefix nì- drops before the plural prefix ay+, though there is no change in writing. So, nìayfo like them is pronounced as nayfo. [2]
2.3.7.2
The vowel in nì- will usually elide before a stressed e, as in nì- + etrìp > netrìp. If the e is unstressed, it will usually, though not always, elide, nì- + eyawr > nìyawr. One exception: nìean instead of the expected *nean.
2.3.8 - Other Phonetic Processes
2.3.8.1
In colloquial speech names containing the sequence o’a may eliminate the glottal stop, such as Mo’at ~ Moat and Lo’ak ~ Loak. [3]