The Sko or Skou languages are a small language family spoken by about 7000 people, mainly along the coast of Sandaun Province in Papua New Guinea, with a few being inland from this area and at least one just across the border in the Indonesian province of Papua (formerly known as Irian Jaya).
Skou languages are unusual among Papuan languages for being tonal; all Skou languages possess contrastive tone.Vanimo, for example, has three tones, high, mid, low.
Lakes Plain languages, spoken in a discontiguous area to the southwest, are also tonal. Because of the apparent phonological similarities and sharing of stable basic words such as ‘louse’, Foley speculates the potential likelihood of a distant relationship shared between the Skou and Lakes Plain families, but no formal proposals linking the two families have been made due to insufficient evidence. Additionally according to Foley, based on some lexical and phonological similarities, the Keuw language (currently classified as a language isolate) may also possibly share a deep relationship with the Lakes Plain languages.
Example minimal sets illustrating tonal contrasts in various Skou languages:
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^ abcdeFoley, William A. (2018). "The Languages of the Sepik-Ramu Basin and Environs". In Palmer, Bill (ed.). The Languages and Linguistics of the New Guinea Area: A Comprehensive Guide. The World of Linguistics. 4. Berlin: De Gruyter Mouton. pp. 197–432. ISBN978-3-11-028642-7.
^Foley, William A. (2018). "The languages of Northwest New Guinea". In Palmer, Bill (ed.). The Languages and Linguistics of the New Guinea Area: A Comprehensive Guide. The World of Linguistics. 4. Berlin: De Gruyter Mouton. pp. 433–568. ISBN978-3-11-028642-7.
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^Miller, Steve A. 2017. Skou Languages Near Sissano Lagoon, Papua New Guinea. Language and Linguistics in Melanesia 35: 1-24.
Laycock, Donald C. (1975). "Sko, Kwomtari, and Left May (Arai) phyla". In Stephen A. Wurm (ed.). Papuan languages and the New Guinea linguistic scene: New Guinea area languages and language study 1. Canberra: Dept. of Linguistics, Research School of Pacific Studies, Australian National University. pp. 849–858. OCLC37096514.
Ross, Malcolm (2005). "Pronouns as a preliminary diagnostic for grouping Papuan languages". In Andrew Pawley; Robert Attenborough; Robin Hide; Jack Golson (eds.). Papuan pasts: cultural, linguistic and biological histories of Papuan-speaking peoples. Canberra: Pacific Linguistics. pp. 15–66. ISBN0858835622. OCLC67292782.