Arosi is a Southeast Solomonic language spoken on the island of Makira. Arosi is primarily spoken by inhabitants who live to the west of the Wango River on Makira (formerly known as San Cristobal Island). Makira is in the easternmost part of the Solomon Islands. Makira was visited and named by Álvaro de Mendaña de Neira in 1588. Upon landing on Makira, the Spanish were the first to record Arosi, but only six words were initially recorded. Arosi is one of the lesser known languages in Melanesia.

Arosi distinguishes 5 vowels and 17 consonants, including the velar nasal [ŋ] and the glottal stop. Unlike many other Oceanic languages, /b/, /bʷ/, /d/, and /g/ are not nasalized. Although there is a [j] sound in Arosi, it is not distinguished in writing from the vowel /i/. The chart below shows the consonants in Arosi. For the most part, the spelling of words in Arosi is phonemic.

Sounds /k, ɡ/ can have labialized allophones [kʷ, ɡʷ] when before rounded vowels.

Syllables never end in a consonant; every syllable has either V or CV structure. The table below shows examples illustrating different types of syllable structure in Arosi:

Arosi words can bear two types of stress:

Compared to English and other Western European languages, Arosi's intonation tends to waver from higher to lower tones more quickly rather than steadily increasing.

Arosi sentences can be divided into two basic types: major sentences and minor sentences.

Major sentences include a predicate, and at least one verb form. Major sentences can also be broken down into three categories: simple, compound, and complex. Major sentences consist of a noun phrase (NP) and verb phrase (VP). The subject of the sentence can often be broken down into these two types of phrases. Linking the two phrases (NP + VP) creates a compound sentence. Finally, complex sentences are made of compound sentences with subordinate clauses to the main phrase of the sentence.