Sobei is one of the Sarmi languages spoken in three villages (Sarmi, Sawar, and Bagaiserwar) near the district center of Sarmi in Papua province of Indonesia. Ethnologue (2005) cites two third-party population estimates of 1,000 and 1,850, while Sterner estimates the population at 1,500 (1975) and 2,000 (1987), based on actual residence in the area.
Sobei reflexes of some common Austronesian etyma include ima 'hand', betwe 'star', daidu 'two', faso 'paddle', fau 'four', mam 'father', nen 'mother', natu '(his/her) child', niwe 'coconut', pana 'food', puwe 'betelnut', rani 'water', rau 'leaf', -sa 'up', -si 'down', siso 'breast', tafi 'sugarcane', tano 'rain', temto 'man', tesese 'one', tou 'three', wane 'sand', yafu 'fire' (all gleaned from J. Sterner 1975).
Sobei distinguishes alienable possession from inalienable possession by directly suffixing nouns in the latter type of relationship, principally body parts and kin terms. The morphophonemics are often complex: natu’ 'my child', natun 'his/her child', netrirse 'our child(ren)', netrise 'their child(ren)'; dabu'sa'a 'my head', dabusa'a 'his/her head', debrirsa'a 'our heads', debrisa'a 'their heads' (Sterner 1987). The following paradigm of the inalienably possessed noun tema- 'father' is from Sterner (1976). The intermediate -ri- before the possessive suffix serves as a plural marker. As an independent pronoun, ri is 3rd person plural ('they'). Some kin terms that do not take the possessive suffixes nevertheless have plural forms ending in -(r)i: wawa-ri 'uncle-PL', tinan-i 'mother-PL', nabai-yi 'cousin-PL' (Sterner 1976).
Sobei verb stems can include a number of aspectual, reciprocal, modificational, or directional affixes, but every verb is minimally prefixed to show the grammatical person and number of its subject and grammatical mood (realis or irrealis). Mood markers differ according to whether the stem is simple or complex, and some classes of verbs show stem allomorphy in their conjugational paradigms. (See Sterner 1987.)