| Sepik | |
|---|---|
| Sepik River | |
| Geographic distribution | Sepik River region, northern Papua New Guinea (mostly in East Sepik Province) |
| Linguistic classification | One of the world's primary language families |
| Subdivisions | |
| Glottolog | sepi1257 |
 Distribution of Sepik languages in Papua New Guinea | |
The Sepik or Sepik River languages are a family of some 50 Papuan languages spoken in the Sepik river basin of northern Papua New Guinea, proposed by Donald Laycock in 1965 in a somewhat more limited form than presented here. They tend to have simple phonologies, with few consonants or vowels and usually no tones.
The best known[by whom?] Sepik language is Iatmul. The most populous are Iatmul's fellow Ndu languages Abelam and Boiken, with about 35,000 speakers each.
The Sepik languages, like their Ramu neighbors, appear to have three-vowel systems, /ɨ ə a/, that distinguish only vowel height in a vertical vowel system. Phonetic [i e o u] are a result of palatal and labial assimilation to adjacent consonants. It is suspected that the Ndu languages may reduce this to a two-vowel system, with /ɨ/ epenthetic (Foley 1986).