[2][3] That the Arbore language belongs within a "Macro-Somali" (now called Omo-Tana) group was first recognized by Sasse (1974).
Other members of this group are Daasanach, Bayso, Rendille, Boni and the various Somali dialects.
Arbore's nearest relatives (jointly classified as Western Omo-Tana) are Daasanach and especially the probably extinct Kenyan language of the Elmolo fishermen of Lake Turkana.
The differences follow certain patterns and these patterns are:[10] Arbore well exemplifies a number of typical Lowland East Cushitic features such as: a three-term number system (basic unit: singulative: plural) in nouns, within which "polarity" figures, i.e., gender alternations across the various number forms of a lexeme; a morphosyntax thoroughly deployed in distinguishing topic and contrastive focus; great morphophonological complexity in its verbal derivation and inflection.
[11] Of historical interest is the language's preservation of at least a dozen verbs of the archaic "Prefix Conjugation", often attributed to Proto-Afroasiatic itself.
Additionally, there is a fairly large group of mostly feminine nouns with an h-tone in the end, to which -n is suffixed in the plural.
In the predicative function, adjectives only have one form which does not change depending on the gender of the subject noun.
[17] There are the following patterns of suffix conjugation:[18] In Arbore, there are two types of prepositions.
The first type has a nominal origin and is homophonous with nouns denoting either locations or body parts.
Focussed noun phrases take the phrase-final clitic subject pronoun.
Location words, however, appear to be more postpositional in that they occur as heads of genitival constructions, and the clitic-pronoun is attached to them.
They have an inherent gender, even though the phonological shape or tone do not always correlate with their counterparts in nouns.
[20] In neutral sentences, the word order is the following: subject (S); preverbal selections (PVS); complements (if necessary); verb (V).
The masculine and plural marker is independent of the spelling of the head noun.