Arapaho phonology

Among the sound changes in the evolution from Proto-Algonquian to Arapaho are the loss of Proto-Algonquian *k, followed by *p becoming either or ; the two Proto-Algonquian semivowels merging to either  or ; the change from *s to  in word-initial position, and *m becoming  or  depending on the following vowel. Arapaho is unusual among Algonquian languages in retaining the contrast between the reconstructed phonemes *r and *θ (generally as and, respectively). These and other changes serve to give Arapaho a phonological system very divergent from that of Proto-Algonquian and other Algonquian languages, and even from languages spoken in the adjacent Great Basin. Some examples comparing Arapaho words with their cognates in Proto-Algonquian can illustrate this:

Vowels
At the level of pronunciation, Arapaho words cannot begin with a vowel, so where the underlying form of a word begins with a vowel, a prothetic is added.

Arapaho has a series of four short vowels (pronounced ) and four long vowels  (customarily written $\langleii ee oo uu\rangle$ and pronounced ). The difference in length is phonemically distinctive: compare hísiʼ, "tick" with híísiʼ, "day", and hócoo, "steak" with hóócoo, "devil". and are mostly in complementary distribution, as, with very few exceptions, the former does not occur after velar consonants, and the latter only occurs after them. does have some exceptions as in the free variants kokíy ~ kokúy, "gun"; kookiyón ~ kookuyón, "for no reason"; and bííʼoxíyoo ~ bííʼoxúyoo, "Found in the Grass" (a mythological character). There is only one minimal pair to illustrate the contrast in distribution: núhuʼ, "this" versus níhiʼ-, "X was done with Y", in which níhiʼ- only occurs in bound form.

Remarkably, unlike more than 98% of the world's languages, Arapaho has no low vowels, such as.

In addition, there are four diphthongs,, and several triphthongs, as well as extended sequences of vowels such as  with stress on either the first or the last vowel in the combination.

Consonants
The consonant inventory of Arapaho is given in the table below. When writing Arapaho, is normally transcribed as $\langley\rangle$,  as $\langlec\rangle$,  as $\langleʼ\rangle$, and  as $\langle3\rangle$.

Allophony
The phoneme /b/ (the voiced bilabial stop) has a voiceless allophone [p] that occurs before other consonants or at the end of a word. The plosives, /k/, and /t/ are pronounced without aspiration in most environments, but are aspirated before other consonants or at the end of a word, or when preceding a syllable-final sequence of short vowel + /h/. In this same environment /b/ is aspirated and devoiced. For example, the grammatical prefix cih- is pronounced, the grammatical prefix tih- is pronounced , and the word héétbihʼínkúútiinoo, "I will turn out the lights" is hetihʼínkúútiinoo.

Consonant clusters
Consonant clusters in Arapaho can only be two consonants long. Consonant clusters do not occur word initially, and /hC/ is the only that occurs word finally. The only consonant cluster that is "base generated" (exists in the most underlying representation of words) is /hC/. At the "surface" (at the level of actual pronunciation), other clusters arise by phonological processes including vowel syncope, or by juxtaposition of morphemes.

Prosody
Arapaho is a pitch-accent language. There are two phonemic tones: high (marked with an acute accent) or "normal" (unmarked). The contrast can be illustrated with the pair hónoosóóʼ, "it is fancy" and honoosóóʼ, "it is raining." Long vowels and vowel sequences can carry a contour tone from high to low, as in hou3íne-, "to hang" (where the first syllable has a normal tone) versus hóu3íne-, "to float" (where the first syllable has a high+normal, or falling, tone). Although tonal contrasts are distinctive in Arapaho, minimal pairs such as those listed above are rare.