The Volta–Niger family of languages, also known as West Benue–Congo or East Kwa, is one of the branches of the Niger–Congo language family, with perhaps 70 million speakers. Among these are the most important languages of southern Nigeria, Benin, Togo, and southeast Ghana: Yoruba, Igbo, Bini, and Gbe.
| Volta–Niger | |
|---|---|
| West Benue–Congo or East Kwa | |
| Geographic distribution | West Africa, from Eastern Ghana to central Nigeria |
| Linguistic classification | Niger–Congo?
|
| Subdivisions |
|
| Language codes | |
| Glottolog | None |
 Map cut-out of Volta-Niger family of languages area, with most of the languages bounded by the Volta river, in modern-day Ghana, and the Niger river, found in modern-day Nigeria | |
These languages have variously been placed within the Kwa or Benue–Congo families or, starting in the 1970s, combined with them altogether. Williamson & Blench (2000) separate the languages here called Volta-Niger from the others. Güldemann (2018) fails to see clear criteria for dividing the languages into two or three families and maintains the broad grouping and name of Benue-Kwa for all them.
Branches
editThe constituent groups of the Volta–Niger family, along with the most important languages in terms of number of speakers, are as follows (with number of languages for each branch in parentheses):[according to whom?]
Volta–Niger
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The Yoruboid languages and Akoko were once linked as the Defoid branch, but more recently they, Edoid, and Igboid have been suggested to be primary branches of an as-yet unnamed group, often abbreviated yeai. Similarly, Oko, Nupoid, and Idomoid are often grouped together under the acronym noi. Ukaan is an Atlantic–Congo language, but it is unclear if it belongs to the Volta–Niger family; Blench suspects it is closer to Benue–Congo.
In an automated computational analysis (ASJP 4) by Müller et al. (2013):[1]
Branches and locations
edit
Below is a list of major Volta–Niger branches and their primary locations (centres of diversity) in Nigeria based on Blench (2019).[2]
| Branch | Primary locations |
|---|---|
| Akpes | Akoko North LGA, Ondo State |
| Ayere–Ahan | Akoko North LGA, Ondo State |
| Gbe | Badagry LGA, Lagos State and adjacent areas |
| Yoruboid | Southwestern Nigeria |
| Edoid | Rivers, Edo, Ondo, Delta States |
| Akoko | Akoko North LGA, Ondo State |
| Igboid | Anambra, Rivers, Delta States (excluding Igbo proper) |
| Nupoid | Niger, Kwara, Nasarawa States |
| Oko | Okene LGA, Kogi State |
| Idomoid | Benue, Cross River, Nasarawa States |
| Ukaan | Akoko North LGA, Ondo State |
Comparative vocabulary
edit
Sample basic vocabulary in different Volta–Niger branches:
| Language | eye | ear | nose | tooth | tongue | mouth | blood | bone | tree | water | eat | name |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Yoruba | ojú | etí | imú | eyín | ahọ́n | ẹnu | ẹ̀jẹ | egungun | igi | omi | jẹ | orúkọ |
| Proto-Yoruboid[3] | *e-jú | *e-tĩ́ | *ɪ-ŋmʊ̃́ | *e-ɲĩ́ | *ʊ-ɓã́ | *a-rʊ̃ã | *ɛ̀-byɛ̀ | *V-k'ĩk'ũ | *e-gĩ (i-) | *o-mĩ | *jɛ | *o-ɗú |
| Proto-Yoruboid[4] | *éjú | *étí | *ímṵ́ | *éŋḭ́ | Yor. ahá̰ | *ɛ́lṵ ? | *ɛ̀gyɛ̀ | *égbṵ́gbṵ́ | Yor. igi | *ómḭ | *jɛṵ | *órú- ? |
| Proto-Edoid[5] | *dhI-dhω | *ghU-chɔGɪ | *I-chuəNi; *-chuveNi | *dhI-kωN | *U-dhamhɪ | *A-nuə | *U-ɟɪ-, -ɟɪa | *U-thaNɪ | *A-mɪN | *dhɪ | *dhI-ni | |
| Proto-Gbe[6] | *-tó | *aɖú | *-ɖɛ́ | *-ɖũ; *-ɖũkpá | *-ʁʷũ | *-χʷú | *-tĩ́ | *-tsĩ | *ɖu | *yĩ́kɔ́ | ||
| Akoko (Arigidi)[7] | ódʒù | oto | (odʒ)uw̃ɔ̃̀ | éɲì̃ | ɛŕɛ̀ | õrũ | ɛ̀dʒɛ̀ | ɛ̀dʒɛ̀ | ɔ́hɔ̃̄ | edʒĩ | dʒō | |
| Proto-Akpes;[8] Akpes (Ajowa)[9] | *èyò | *àsùgù | *àhũ | *ìyũ | *ìndàlì | *onu | ìkɔ̃̀n | ɔhuni | imi | ìmũ̀nũ̀ | ||
| Ayere[10] | ɛ́jɛ́ | éndí | ówṹ | éyĩ́ | únú | anu | èʃwè | egbe | oŋwu | oyin | ʃe | éwú |
| Ahan[10] | ewú | éndí | owũ | eɲĩ | irɛ̃́ | arũ | èsè | igbegbe | oɲĩ | |||
| Proto-Nupoid[11] | *e-wie | *CV-tuNukpua | *V-bhʊə | *jiNkɔN | *a-giNtara | *V-giə | *CV-kiukuNu | *V-cigbɔNa | *nuNŋʷa | *gi | *CV-jɛ | |
| Proto-Ebiroid[11] | *e-ji | *ʊ-tɔkpa | *a-ʃɪ | *a-ɲɪ | *ɪra-rɛ | *aɲa | *ʧʊku | *ɔ-tʃɪ | *e-ɲi | *rɪ | *ɪrɛ-ʃa | |
| Oko[12] | áɲẽ́ | ɔ́tɔ̃́ | ɔ́mɔ́dɔ́rɛ̀ | írú | ɛ́làárɛ́ | ówó | ɛ́ŋɔ̂ | ófú | esáma | ébí | jé | íwúrù |
| Proto-Idomoid[13] | *eyi | *ʊrʊ/a- | *eŋgwu | *ìmàǹjī | *ìmànyì; *ma-yeni ? | *ri | *ɛɲɪ | |||||
| Proto-Ukaan[14] | *ìdʒì | *ʊrʊgV | *ɔ̀kɔ̃́rɔ̃̀ | *ʊ̀ɲʊ̀gV; jɔ̀r | *ɛ̀ɲʊ̃́ | *òŋʷṍ | *ùɲṹ | *òɣʷó | *ɔ̀hʊ̃́nṽ | *ùmɔ̃̀ | *jé | *ìnĩ́ |
| Proto-Benue–Congo[15] | *-lito | *-tuŋi | *-zua | *-nini, *-nino; *-sana; *-gaŋgo (±) | *-lemi; *-lake | *-zi; *-luŋ | *-kupe | *-titi; *-kwon | *-izi (±); *-ni (±) | *-zina |
Numerals
editComparison of numerals in individual languages:[16]
| Classification | Language | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Akpes | Akpes | íɡbōn / ēkìnì | īdīan(ì) | īsās(ì) | īnīŋ(ì) | īʃōn(ì) | ītʃānās(ì) | ītʃēnētʃ(ì) | ānāānīŋ(ì) | ɔ̀kpɔ̄lɔ̀ʃ(ì) | īyōf(ì) |
| Defoid, Akokoid | Ariɡidi (Iɡasi) | [kɛ̀ɛ́ɲɛ̃] | [kèji] | [kedà] | [kenɛ] | [kéntɔ̀] | [kefà] | [keɸi] | [kerò] | [kéndà] | [kéjè] |
| Defoid, Akokoid | Òɡè | [ékán] | [ìyí] | [ídaː] | [ínɛ́] | [ítɔ̃̀] | [ìfà] | [ídʒúí] | [írò] | [ĩ́ŋa] | [íyè] |
| Defoid, Ayere-Ahan | Ayere (Úwû) | ĩ̀kã̌ | ìd͡ʒì | ītā | ĩ̄jẽ̄ | ĩ̄tṹ | ìfà | īd͡ʒʷī | īrō | ĩ̄dã̂ | īɡʷá |
| Defoid, Ayere-Ahan | Ayu | ɪdɪ | ahwa /afah | ataar | anaŋaʃ | atuɡen | atɛɛr | ataraŋaʃ (3 ?) | anababoɡ (4 ?) | atuluboɡ (5 ?) | iʃoɡ / ajalaboɡ |
| Defoid, Yoruboid, Edekiri | Cabe (Ede Cabe) | ɔ̀kɛ̃ | mɛ̃́d͡ʒì | mɛ̃́ta | mɛ̃́hɛ̃ | mɛ́hú | mɛ̃́fà | méd͡ʒe | mɛ̃́d͡ʒɔ | mɛ̃́sɛ̃́ | mɛ̃́wá |
| Defoid, Yoruboid, Edekiri | Ede Ica (Ica) | ɔkɔ̃ | eɟi | ɛta | ɛ̃ɛ̃ | ɛwu | ɛfa | ɛɟɛ | ɛɟɔ | ɛsɔ̃ | ɛya |
| Defoid, Yoruboid, Edekiri | Idaca (Ede Idaca) | òbú | méd͡ʒi | mɛ́ta | mírĩ | mɛrú | mɛ́fà | méd͡ʒe | mɛ́d͡ʒɔ | mɛ́sã | maa |
| Defoid, Yoruboid, Edekiri | Ifè (1) | ɛnɛ́ | méèdzì | mɛ́ɛta | mɛ́ɛrɛ̃ | mɛ́ɛrú | mɛ́ɛfà | méedze | mɛ́ɛdzɔ | mɛsã́ | maá |
| Defoid, Yoruboid, Edekiri | Ifè (2) | ɛ̀nɛ / ɔ̀kɔ̃̀ | méèdzì | mɛ́ɛta | mɛ́ɛrɛ̃ | mɛ́ɛrú | mɛ́ɛfà | méedze | mɛ́ɛdzɔ | mɛsã́ | maá |
| Defoid, Yoruboid, Edekiri | Ulukwumi | ɔ̀kɑ̃ | mɛ́zì | mɛ́tɑ | mɛ́rɛ̃ | mɛ́rú | mɛ́fɑ̀ | méze | mɛ́zɔ | mɛ̀hɑ̃́ | mɛ́ɡʷɑ́ |
| Defoid, Yoruboid, Edekiri | Yoruba | oókan [oókɔ̃] | eéjì [eéɟì] | ẹẹ́ta [ɛɛ́ta] | ẹẹ́rin [ɛɛ́ɾĩ] | aárùn-ún [aáɾũ̀ṹ] | ẹẹ́fà [ɛɛ́fà] | eéje [eéɟe] | ẹẹ́jọ [ɛɛ́ɟɔ] | ẹẹ́sàn-án [ɛɛ́sɔ̃̀ɔ̃́] | ẹẹ́wàá [ɛɛ́wàá] |
| Defoid, Yoruboid, Igala | Igala (1) | éɲɛ́ / ǒkâ | èdʒì | ɛ̀ta | ɛ̀lɛ̀ | ɛ̀lú | ɛ̀fà | èbʲe | ɛ̀dʒɔ | ɛ̀lá | ɛ̀ɡʷá |
| Defoid, Yoruboid, Igala | Igala (2) | ínyé̩ [íɲɛ́] | èjì [èdʒì] | ẹ̀tā [ɛ̀tā] | ẹ̀lè̩ [ɛ̀lɛ̀] | è̩lú [ɛ̀lú] | ẹ̀fè̩ [ɛ̀fɛ̀] | ẹ̀biē [èbjiē] | ẹ̀jọ̄ [ɛ̀dʒɔ] | ẹ̀lá [ɛ̀lá] | ẹ̀ɡwá [ɛ̀ɡwá] |
| Ukaan | Ukaan (Ikaan dialect) | ʃí | wā | tāːs / hrāhr | nāʲ / nā | hrʊ̀ːn / tòːn | hràdá | hránèʃì | nàːnáʲ / nàːná | hráòʃì | òpú * |
| Edoid, Delta | Degema | ɔβʊ́ | iβə́ | sáj (ɪsáj) | iní | súwón (ɪsúwón) | jɪ́sa (ɪjɪ́sá) | síjéβə (isíjéβá) | anɪ́ (ɪnʊ́mán) | əsí (ɔβʊ óte mʊ iɡ͡beɲ) (10 -1) | əɡ͡beɲ (iɡ͡béɲ) |
| Edoid, Delta | Engenni | ávʊ̀ | ívà | ɛ́sàà | ínìì | ìsyònì | ɛ̀nyísà | ìsyovà | ɛ̀nʊ̀màní | àvʊ́mó (10 -1) | íɡ͡bèì |
| Edoid, North-Central, Edo-Esan-Ora | Ẹdo (1) | òwó [òwó] (used only to count) | èvá [èvá]́ | èhá [èhá] | èné [ènɛ́] | ìsén [ìsɛ́] or [ìsɛ̃́] ?? | èhàn [èhã̀] | ìhírọ̃n [ìhĩɺɔ]̃ | èrẹ̀nrẹ̀n [èɺɛ̃ɺɛ̃] | ìhìnrín [ihĩɺĩ] | ìɡ͡bé [ìɡ͡bé] |
| Edoid, North-Central, Edo-Esan-Ora | Edo (Bini) (2) | ɔ̀k͡pá / òwo (used only to count) | èvá | èhá | ènɛ́ | ìsɛ́n | ěhàn | ìhinrɔ̀n | èrɛ̀nrɛ́n | ìhìnrín | ìɡ͡bé |
| Edoid, North-Central, Edo-Esan-Ora | Emai (Emai-luleha-Ora) | ɔ̀k͡pa | èvà | èéà | èélè | ìíhìɛ̀n | èéhàn | ìhíɔ́n | èɛ́n | ìsín | ìɡ͡bé |
| Edoid, North-Central, Edo-Esan-Ora | Esan | ɔ̀k͡pá | èvá | éà | énɛ̃̀ | ìsɛ̃́ | éhã́ | ìhĩ́lɔ̃̀ | èlɛ̃́lɛ̃̀ | ĩ̀sɪ̃́lɪ̃̀ | ìɡ͡bé |
| Edoid, North-Central, Ghotuo-Uneme-Yekhee | Etsako (Yekhee) | ọkpa [ɔk͡pà] | eva [évà] | ela [élà] | ejiẹ [éʒié] | ise [ìsé] | esa [ésà] | isevha [ìsévhà] | eleeh [éːléː] | ithi [ìtií] | iɡbe [ìɡ͡bé]̄ |
| Edoid, North-Central, Ghotuo-Uneme-Yekhee | Ghotuo | ɔ̀k͡pā | èvā | èēsà | èēnè | ìīʒè / ìīʒìè | ìjhēhà / ìēhà jh = a week, vd | ìhīɲã̄ | ènhīē nh = n̥ voiceless n ? | ìsī | ìɡ͡bē LM͡L |
| Edoid, North-Central, Ghotuo-Uneme-Yekhee | Okphela (1) | oɡ͡ɣʷo ˥˩ ˨ | evɑ ˨ ˧ | esɛ ˧ ˨ | ene ˧ ˨ | iʃe ˧ ˨ | esesa ˨ ˧ ˨ | iʃilʷɑ ˨ ˧ ˨ | elele ˨ ˩˥ ˨ | itili ˨ ˩˥ ˧ | iɡ͡be ˨ ˧ |
| Edoid, North-Central, Ghotuo-Uneme-Yekhee | Ivbie-North-Okphele-Arhe (2) | oɣuo | eva | esɛ | ene | iʃie | esesa | iʃilua | elele | itili | iɡ͡be |
| Edoid, North-Central, Ghotuo-Uneme-Yekhee | Ososo | oɡwo [òɡwò] | eva [èvá] | esa [èsá] | ene [èné] | ichie [ìt͡ʃè] | esesa [èsâsà] | ifuena [ìfwènà] | inyenye [ìɲèɲẽ́] | isini [ìsĩ̀nĩ̀] | iɡbe [ìɡ͡bé] |
| Edoid, Northwestern, Southern | Okpamheri | ɔkpa | eva | esa | enen | ishe | eaza | izuonua | ɛnien | isie | iɡ͡be |
| Edoid, Southwestern | Isoko (1) | ɔvʊ | ɪ́vɛ | ɪ́sa | ɪ́nɪ | ɪ́sɔɪ | ɪ́zɪ́za | ɪ́hɾɛ | ɪ́rɪ́ː | ɪ́zɪ́ː | ɪ́kpe |
| Edoid, Southwestern | Isoko (2) | ọvụ | ịvẹ | ịsạ | ịnị | isoi | ịzịza | ihrẹ | ịrịị | izii | ikpe |
| Edoid, Southwestern | Urhobo | ɔ̀vò | ǐvɛ̀ | ěrà | ɛ̌nè | ǐjòɾĩ̀ | ěsã́ | ǐɣwɾɛ̃́ | ɛ̌ɾéɾẽ | ǐríɾĩ | ǐxwè |
| Igboid, Ekpeye | Ekpeye | nwùrnér, ŋìnɛ́ | ɓɨ̂bɔ́ bh = IPA [ɓ] | ɓɨ́tɔ́ ir = IPA [ɨ] | ɓɨ́nɔ̂ o̠r = IPA [ɔ] | ɓísê | ɓísû | ɓɨ́sábɔ̀ | ɓɨ́sátɔ́ | ɓɨ́sánɔ̂ or nàzáma or nàzáma ɗi | ɗì dh = IPA [ɗ] |
| Igboid, Igbo | Igbo (1) | ótù | àbʊ̄ɔ́ | àtɔ́ | ànɔ́ | ìsé | ìsiì | àsáà | àsátɔ́ | ìtólú | ìri |
| Igboid, Igbo | Échiè Igbo (2) | otù | àbʊ̀ɔ́ ~ m̀bʊ̀ɔ̀ ~ nam̀̀ | tɔ ~ àtɔ | (ǹ)nɔ ~ ànɔ | se~ ìse | ʃiì ~ ìʃiì | saà ~ àsaà | satɔ̄ ~ àsatɔ̄ | totū ~ ìtolū | ìri |
| Igboid, Igbo | Igbo (3) | otù | àbʊɔ́ | àtɔ | ànɔ | ìse | ìsiì | àsaà | àsatɔ́ | ìtolú, ̀tolú | ìri |
| Igboid, Igbo | Ikwere | ótù | ɛ̀bɔ̀ | ɛ̀tɔ́ | ɛ̀nɔ̂ | ìsẽ̂ | ìsínù | ɛ̀sâ | ɛ̀sátɔ́ | tólú | ǹrí |
| Oko | Oko (Oko-Eni-Osayen) | ɔ̀ɔ́rɛ / ɔ̀jɛ́rɛ | ɛ̀bɔ̀rɛ̀ | ɛ̀ta | ɛ̀na | ùpi | ɔ̀pɔ́nɔ̀ɔ́rɛ (5 + 1) * | úfɔ́mbɔ̀rɛ̀ (5 + 2) * | ɔ̀nɔ́kɔ́nɔkɔ́nɔ | ùbɔ́ɔ̀rɛ̀ (< 'ten is less than one ') * | ɛ̀fɔ |
| Nupoid, Ebira-Gade | Ebira | ɔ̀ɔ̀nyɪ̄ | ɛ̀ɛ̀vā | ɛ̀ɛ̀tá | ɛ̀ɛ̀nà | ɛ̀ɛ̀hɪ́ | hɪ̋nɔ̋nyɪ̄ (5+ 1) | hɪ̋m̋bā (5+ 2) | hɪ̋n̋tá (5+ 3) | hɪ̋ǹnà (5+ 4) | ɛ̀ɛ̀wʊ́ |
| Nupoid, Nupe-Gbagyi, Gbagyi-Gbari | Gbari | ɡ͡bᵐaːɾí | ŋʷã̂ba | ŋʷã̂t͡ʃa | ŋʷã̂ɲi | ŋʷã̂tⁿù | tⁿúwĩ (5+ 1) | tⁿâba (5+ 2) | tⁿẫ̂t͡ʃa (5+ 3) | tⁿâɲi (5+ 4) | ŋʷã̂wò |
| Nupoid, Nupe-Gbagyi, Nupe | Kakanda | ɡúní | ɡúbà | ɡútá | ɡúni | ɡútũ | ɡútuaɲĩ̀ (5+ 1) | ɡútuabà (5+ 2) | ɡútòtá (5+ 3) | ɡútuani (5+ 4) | ɡúwo |
| Nupoid, Nupe-Gbagyi, Nupe | Nupe | niní | ɡúbà | ɡútá | ɡúni | ɡútsũ | ɡútswàɲĩ (5+ 1) | ɡútwàbà (5+ 2) | ɡútotá (5+ 3) | ɡútwã̀ni (5+ 4) | ɡúwo |
| Idomoid, Akweya, Eloyi | Eloyi (Afo) (1) | ńɡwònzé | ńɡwòpó | ńɡwòlá | ńɡwòndó | ńɡwolɔ́ | ńɡwɔ̀rɛ́nyí | ńɡwòrówó | ńɡwòràndá | ńɡwòròndó | úwó |
| Idomoid, Akweya, Eloyi | Eloyi (Afo) (2) | ònzé | òpā | ōlá | ōndō | ɔ̄lɔ̀ o̠= ɔ | ōròwò | ɔ̀rɛ̀nyi | ōràndá | òròndō | ūwó |
| Idomoid, Akweya, Eloyi | Eloyi (3) | ònzé | òpā | ōlá | ōndō | ō̠lò̠ | ōròwò | ò̠rɛ̀nyi | ōràndá | òròndō | ūwó |
| Idomoid, Akweya, Etulo-Idoma, Idoma | Agatu | óyè [ɔ́jè] | ẹ̀pà [ɛ̀pà] | ẹ̀tá [ɛ̀tá] | ẹ̀nẹ̀ [ɛ́nɛ̀] | ẹ̀họ́ [ɛ̀hɔ́] | ẹ̀hílí [ɛ̀hílí] | àhápà [àhápà] | àhàtá [àhàtá] | àhànè [àhànè] | ìɡwó [ìɡwó ] |
| Idomoid, Akweya, Etulo-Idoma, Idoma | Alago | óje | èpà | èta | ènɛ̀ | ɛ̀hɔ | ìhirì | àhapà | àhatá | àhánɛ̀ | ìɡʷó |
| Idomoid, Akweya, Etulo-Idoma, Idoma | Idoma | éyè [éjè] | ẹpà [ɛ́pà] | ẹtá [ɛtá] | ẹhẹ [ɛ́hɛ́] | ẹhọ [ɛ́hɔ] | ẹhili [ɛ́hili] | àhapà [àhapà] | àhátá [àhátá] | àhánẹ [àhánɛ́] | iɡwó [iɡwó ] |
| Idomoid, Akweya, Etulo-Idoma, Idoma | Igede | óòk͡pók͡póh | îmíìyèh | ītā | īnêh | ērʊ̄ / īrʊ̄ | īrʷɔ̀nyɛ̀ | īrùyèh | īnêkúh | ìhíkítʃú | īwō |
| Idomoid, Akweya, Etulo-Idoma, Idoma | Yala | ósè | ɛ̀pà | ɛ̀ta | ɛ̀nɛ̀ | èrwɔ | èríwi | àrapà | àratá | àranɛ̀ | ìɡwó |
See also
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References
edit- ^ Müller, André, Viveka Velupillai, Søren Wichmann, Cecil H. Brown, Eric W. Holman, Sebastian Sauppe, Pamela Brown, Harald Hammarström, Oleg Belyaev, Johann-Mattis List, Dik Bakker, Dmitri Egorov, Matthias Urban, Robert Mailhammer, Matthew S. Dryer, Evgenia Korovina, David Beck, Helen Geyer, Pattie Epps, Anthony Grant, and Pilar Valenzuela. 2013. ASJP World Language Trees of Lexical Similarity: Version 4 (October 2013).
- ^ a b Blench, Roger (2019). An Atlas of Nigerian Languages (4th ed.). Cambridge: Kay Williamson Educational Foundation.
- ^ Akinkugbe, Olufẹmi Odutayo. 1978. A comparative phonology of Yoruba dialects, Iṣẹkiri and Igala. Doctoral dissertation, University of Ibadan.
- ^ Aubry, N., H. Friedman & K. Pozdniakov. 2004. Proto-Yoruba-Igala Swadesh list. Manuscript. Paris: Langage, Langues et Cultures d’Afrique (LLACAN), Centre National de la Récherche Sciéntifique (CNRS).
- ^ Elugbe, Ben Ohiọmamhẹ. 1989. Comparative Edoid: phonology and lexicon. Delta Series No. 6. Port Harcourt: University of Port Harcourt Press.
- ^ Capo, Hounkpati B.C. 1991. A Comparative Phonology of Gbe. Publications in African Languages and Linguistics, 14. Berlin/New York: Foris Publications & Garome, Bénin: Labo Gbe (Int).
- ^ Fadọrọ, Jacob Oludare. 2010. Phonological and lexical variations in Akokoid. Doctoral dissertation, University of Ibadan.
- ^ Blench, Roger. 2011. Comparative Akpes. m.s.
- ^ Ibrahim-Arirabiyi, Femi 1989. A comparative reconstruction of Akpes lects: Akoko North, Ondo State. MA thesis. Department of Linguistics and Nigerian Languages, University of Port Harcourt.
- ^ a b Blench, Roger. 2007. The Ayere and Ahan languages of Central Nigeria and their affinities.
- ^ a b Bankale, Oyetayo Abiodun. 2006. Comparative Ebiroid and Nupoid. Doctoral dissertation, University of Ibadan.
- ^ Jungraithmayr, Herrmann. 1973. Eine Wortliste des Ọkọ, der Sprache von Ogori (Nigeria). Africana Marburgensia 6: 58-66.
- ^ Armstrong, Robert G. 1983. The Idomoid Languages of the Benue and Cross River Valleys. Journal of West African Languages 13: 91-147.
- ^ Abiodun, Michael Ajibola. 1999. A comparative phonology and morphology of Ukaan dialects of Old Akoko division. Doctoral dissertation. University of Ilorin.
- ^ de Wolf, Paul. 1971. The Noun-Class System of Proto-Benue-Congo. Janua Linguarum. Series Practica 167. The Hague: Mouton.
- ^ Chan, Eugene (2019). "The Niger-Congo Language Phylum". Numeral Systems of the World's Languages.
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- Williamson, Kay (1989) 'Benue–Congo Overview', pp. 248–274 in Bendor-Samuel, John & Rhonda L. Hartell (eds.) The Niger–Congo Languages — A classification and description of Africa's largest language family. Lanham, Maryland: University Press of America.
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