Niger–Congo languages
This article has an unclear citation style. (March 2014) |
Niger–Congo | |
---|---|
Niger–Kordofanian (obsolete) | |
Geographic distribution | Sub-Saharan Africa |
Linguistic classification | One of the world's primary language families |
Subdivisions |
|
Language codes | |
ISO 639-2 / 5 | nic |
Glottolog | None |
Map showing the distribution of Niger–Congo languages. Brown is the Bantu subfamily. |
The Niger–Congo languages constitute one of the world's major language families, and Africa's largest in terms of geographical area, number of speakers, and number of distinct languages.[1] They may constitute the world's largest language family in terms of distinct languages, although this question is complicated by ambiguity about what constitutes a distinct language.
It is the third largest language family in the world by number of native speakers, behind only the Indo-European languages and Sino-Tibetan languages. A characteristic common to most Niger–Congo languages is the use of a noun class system.[2] The most widely spoken Niger–Congo languages by number of native speakers are Yoruba, Igbo, Fula, Shona and Zulu.
The most widely spoken by number of speakers is Swahili.[1] Some scholars have doubted whether Niger–Congo is a valid linguistically genetic unit or rather a typological grouping, but most specialists today consider it a valid family, although there is no consensus on the subclassification.[3]
History
Classification history
Early classifications
Niger–Congo as it is known today was only gradually recognized as a unity. In early classifications of the languages of Africa, one of the principal criteria used to distinguish different groupings was the languages' use of prefixes to classify nouns, or the lack thereof. A major advance came with the work of Sigismund Wilhelm Koelle, who in his 1854 Polyglotta Africana attempted a careful classification, the groupings of which in quite a number of cases correspond to modern groupings. An early sketch of the extent of Niger–Congo as one language family can be found in Koelle's observation, echoed in Bleek (1856), that the Atlantic languages used prefixes just like many Southern African languages. Subsequent work of Bleek, and some decades later the comparative work of Meinhof, solidly established Bantu as a linguistic unit.
In many cases, wider classifications employed a blend of typological and racial criteria. Thus, Friedrich Müller, in his ambitious classification (1876–88), separated the 'Negro' and Bantu languages. Likewise, the Africanist Karl Richard Lepsius considered Bantu to be of African origin, and many 'Mixed Negro languages' as products of an encounter between Bantu and intruding Asiatic languages.
In this period a relation between Bantu and languages with Bantu-like (but less complete) noun class systems began to emerge. Some authors saw the latter as languages which had not yet completely evolved to full Bantu status, whereas others regarded them as languages which had partly lost original features still found in Bantu. The Bantuist Meinhof made a major distinction between Bantu and a 'Semi-Bantu' group which according to him was originally of the unrelated Sudanic stock.
Westermann, Greenberg and beyond
Westermann, a pupil of Meinhof, set out to establish the internal classification of the then Sudanic languages. In a 1911 work he established a basic division between 'East' and 'West'. A historical reconstruction of West Sudanic was published in 1927, and in his 1935 'Charakter und Einteilung der Sudansprachen' he conclusively established the relationship between Bantu and West Sudanic.
Joseph Greenberg took Westermann's work as a starting-point for his own classification. In a series of articles published between 1949 and 1954, he argued that Westermann's 'West Sudanic' and Bantu formed a single genetic family, which he named Niger–Congo; that Bantu constituted a subgroup of the Benue–Congo branch; that Adamawa–Eastern, previously not considered to be related, was another member of this family; and that Fula belonged to the West Atlantic languages. Just before these articles were collected in final book form (The Languages of Africa) in 1963, he amended his classification by adding Kordofanian as a branch co-ordinate with Niger–Congo as a whole; consequently, he renamed the family Congo–Kordofanian, later Niger–Kordofanian. Greenberg's work on African languages, though initially greeted with scepticism, became the prevailing view among scholars.[4]
Bennet and Sterk (1977) presented an internal reclassification based on lexicostatistics that laid the foundation for the regrouping in Bendor-Samuel (1989). Kordofanian was presented as one of several primary branches rather than being coordinate to the family as a whole, prompting re-introduction of the term Niger–Congo, which is in current use among linguists. Many classifications continue to place Kordofanian as the most distant branch, but mainly due to negative evidence (fewer lexical correspondences), rather than positive evidence that the other languages form a valid genealogical group. Likewise, Mande is often assumed to be the second-most distant branch based on its lack of the noun-class system prototypical of the Niger–Congo family. Other branches lacking any trace of the noun-class system are Dogon and Ijaw, whereas the Talodi branch of Kordofanian does have cognate noun classes, suggesting that Kordofanian is also not a unitary group.
Glottolog (2013) accepts the core with noun-class systems, the Atlantic–Congo languages, apart from the recent inclusion of some of the Kordofanian groups, but not Niger–Congo as a whole. They list the following as separate families:
- Atlantic–Congo, Mande, Dogon, Ijoid, Lafofa, Katla–Tima, Heiban, Talodi, Rashad.
Niger–Congo and Nilo-Saharan
Over the years, several linguists have suggested a link between Niger–Congo and Nilo-Saharan, probably starting with Westermann's comparative work on the 'Sudanic' family in which 'Eastern Sudanic' (now classified as Nilo-Saharan) and 'Western Sudanic' (now classified as Niger–Congo) were united. Gregersen (1972) proposed that Niger–Congo and Nilo-Saharan be united into a larger phylum, which he termed Kongo–Saharan. His evidence was mainly based on the uncertainty in the classification of Songhay, morphological resemblances, and lexical similarities. A more recent proponent was Roger Blench (1995), who puts forward phonological, morphological and lexical evidence for uniting Niger–Congo and Nilo-Saharan in a Niger–Saharan phylum, with special affinity between Niger–Congo and Central Sudanic. However, fifteen years later his views had changed, with Blench (2011) proposing instead that the noun-classifier system of Central Sudanic, commonly reflected in a tripartite general–singulative–plurative number system, triggered the development or elaboration of the noun-class system of the Atlantic–Congo languages, with tripartite number marking surviving in the Plateau and Gur languages of Niger–Congo, and the lexical similarities being due to loans.
Common features
Phonology
Niger–Congo languages have a clear preference for open syllables of the type CV (Consonant Vowel). The typical word structure of Proto-Niger–Congo is thought to have been CVCV, a structure still attested in, for example, Bantu, Mande and Ijoid – in many other branches this structure has been reduced through phonological change. Verbs are composed of a root followed by one or more extensional suffixes. Nouns consist of a root originally preceded by a noun class prefix of (C)V- shape which is often eroded by phonological change.
Consonants
Reconstructions of the consonant set of several branches of Niger–Congo (Stewart for proto-Volta–Congo, Mukarovsky for his proto-West-Nigritic, roughly corresponding to Atlantic–Congo) have posited independently a regular phonological contrast between two classes of consonants. Pending more clarity as to the precise nature of this contrast it is commonly characterized as a contrast between 'fortis' and 'lenis' consonants. Five places of articulation are postulated for the consonant inventory of proto-Niger–Congo: labial, alveolar, palatal, velar, and labial-velar.
Vowels
Many Niger–Congo languages' vowel harmony is based on the [ATR] (advanced tongue root) feature. In this type of vowel harmony, the position of the root of the tongue in regards to backness is the phonetic basis for the distinction between two harmonizing sets of vowels. In its fullest form, this type involves two classes, each of five vowels:
[+ATR] | [−ATR] |
---|---|
[i] | [ɪ][5] |
[e] | [ɛ][5] |
[ə] | [a][5] |
[o] | [ɔ][5] |
[u] | [ʊ][5] |
The roots are then divided into [+ATR] and [−ATR] categories. This feature is lexically assigned to the roots because there is no determiner within a normal root that causes the [ATR] value.[6]
There are two types of [ATR] vowel harmony controllers in Niger–Congo. The first controller is the root. When a root contains a [+ATR] or [−ATR] vowel, then that value is applied to the rest of the word, which involves crossing morpheme boundaries.[7] For example, suffixes in Wolof assimilate to the [ATR] value of the root to which they attach. Some examples of these suffixes that alternate depending on the root are:
[+ATR] | [−ATR] | Purpose |
---|---|---|
-le | -lɛ | 'participant' [6] |
-o | -ɔ | 'nominalizing' [6] |
-əl | -al | 'benefactive' [6] |
Furthermore, the directionality of assimilation in [ATR] root-controlled vowel harmony need not be specified. The root features [+ATR] and [−ATR] spread left and/or right as needed, so that no vowel would lack a specification and be ill-formed.[8]
Unlike in the root-controlled harmony system, where the two [ATR] values behave symmetrically, a large number of Niger–Congo languages exhibit a pattern where the [+ATR] value is more active or dominant than the [−ATR] value.[9] This results in the second vowel harmony controller being the [+ATR] value. If there is even one vowel that is [+ATR] in the whole word, then the rest of the vowels harmonize with that feature. However, if there is no vowel that is [+ATR], the vowels appear in their underlying form.[7] This form of vowel harmony control is best exhibited in West African languages. For example, in Nawuri, the diminutive suffix /-bi/ will cause the underlying [−ATR] vowels in a word to become phonetically [+ATR].[9]
There are two types of vowels which affect the harmony process. These are known as neutral or opaque vowels. Neutral vowels do not harmonize to the [ATR] value of the word, and instead maintain their own [ATR] value. The vowels that follow them, however, will receive the [ATR] value of the root. Opaque vowels maintain their own [ATR] value as well, but they affect the harmony process behind them. All of the vowels following an opaque vowel will harmonize with the [ATR] value of the opaque vowel instead of the [ATR] vowel of the root.[6]
The vowel inventory listed above is a ten-vowel language. This is a language in which all of the vowels of the language participate in the harmony system, producing five harmonic pairs. Vowel inventories of this type are still found in some branches of Niger-Congo, for example in the Ghana Togo Mountain languages.[10] However, this is the rarer inventory as oftentimes there are one or more vowels that are not part of a harmonic pair. This has resulted in seven-and nine-vowel systems being the more popular systems. The majority of languages with [ATR] controlled vowel harmony have either seven- or nine-vowel phonemes, with the most common non-participatory vowel being /a/.[5] It has been asserted that this is because vowel quality differences in the mid-central region where /ə/, the counterpart of /a/, is found, are difficult to perceive. Another possible reason for the non-participatory status of /a/ is that there is articulatory difficulty in advancing the tongue root when the tongue body is low in order to produce a low [+ATR] vowel.[11] Therefore, the vowel inventory for nine-vowel languages is generally:
[+ATR] | [−ATR] |
---|---|
[i] | [ɪ] |
[e] | [ɛ] |
[a] | |
[o] | [ɔ] |
[u] | [ʊ] |
And seven-vowel languages have one of two inventories:
[+ATR] | [−ATR] |
---|---|
[i] | [ɪ] |
[ɛ] | |
[a] | |
[ɔ] | |
[u] | [ʊ] |
[+ATR] | [−ATR] |
---|---|
[i] | |
[e] | [ɛ] |
[a] | |
[o] | [ɔ] |
[u] |
Note that in the nine-vowel language, the missing vowel is, in fact, [ə], [a]'s counterpart, as would be expected.[12]
The fact that ten vowels have been reconstructed for proto-Atlantic, proto-Ijoid and possibly proto-Volta–Congo has led to the hypothesis that the original vowel inventory of Niger–Congo was a full ten-vowel system.[13] On the other hand, Stewart, in recent comparative work, reconstructs a seven-vowel system for his proto-Potou-Akanic-Bantu.[14]
Nasality
Several scholars have documented a contrast between oral and nasal vowels in Niger–Congo.[15] In his reconstruction of proto-Volta–Congo, Steward (1976) postulates that nasal consonants have originated under the influence of nasal vowels; this hypothesis is supported by the fact that there are several Niger–Congo languages that have been analysed as lacking nasal consonants altogether. Languages like this have nasal vowels accompanied with complementary distribution between oral and nasal consonants before oral and nasal vowels. Subsequent loss of the nasal/oral contrast in vowels may result in nasal consonants becoming part of the phoneme inventory. In all cases reported to date, the bilabial /m/ is the first nasal consonant to be phonologized. Niger–Congo thus invalidates two common assumptions about nasals:[16] that all languages have at least one primary nasal consonant, and that if a language has only one primary nasal consonant it is /n/.
Niger–Congo languages commonly show fewer nasalized than oral vowels. Kasem, a language with a ten-vowel system employing ATR vowel harmony, has seven nasalized vowels. Similarly, Yoruba has seven oral vowels and only five nasal ones. However, the recently discovered language of Zialo has nasal equivalent for each of its seven vowels.
Tone
The large majority of present-day Niger–Congo languages are tonal. A typical Niger–Congo tone system involves two or three contrastive level tones. Four level systems are less widespread, and five level systems are rare. Only a few Niger–Congo languages are non-tonal; Swahili is perhaps the best known, but within the Atlantic branch some others are found. Proto-Niger–Congo is thought to have been a tone language with two contrastive levels. Synchronic and comparative-historical studies of tone systems show that such a basic system can easily develop more tonal contrasts under the influence of depressor consonants or through the introduction of a downstep. Languages which have more tonal levels tend to use tone more for lexical and less for grammatical contrasts.
H, L | Dyula–Bambara, Maninka, Temne, Dogon, Dagbani, Gbaya, Efik, Lingala |
H, M, L | Yakuba, Nafaanra, Kasem, Banda, Yoruba, Jukun, Dangme, Yukuben, Akan, Anyi, Ewe, Igbo |
T, H, M, L | Gban, Wobe, Munzombo, Igede, Mambila, Fon |
T, H, M, L, B | Ashuku (Benue–Congo), Dan-Santa (Mande) |
PA/S | Mandinka (Senegambia), Fula, Wolof, Kimwani |
none | Swahili |
Abbreviations used: T top, H high, M mid, L low, B bottom, PA/S pitch-accent or stress Adapted from Williamson 1989:27 |
Morphosyntax
Noun classification
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Niger–Congo languages are known for their system of noun classification, traces of which can be found in every branch of the family but Mande, Ijoid, Dogon, and the Katla and Rashad branches of Kordofanian. These noun-classification systems are somewhat analogous to grammatical gender in other languages, but there are often a fairly large number of classes (often 10 or more), and the classes may be male human/female human/animate/inanimate, or even completely gender-unrelated categories such as places, plants, abstracts, and groups of objects. For example, in Bantu, the Swahili language is called Kiswahili, while the Swahili people are Waswahili. Likewise, in Ubangian, the Zande language is called Pazande, while the Zande people are called Azande.
In the Bantu languages, where noun classification is particularly elaborate, it typically appears as prefixes, with verbs and adjectives marked according to the class of the noun they refer to. For example, in Swahili, watu wazuri wataenda is 'good (zuri) people (tu) will go (ta-enda)'.
Verbal extensions
The same Atlantic–Congo languages which have noun classes also have a set of verb applicatives and other verbal extensions, such as the reciprocal suffix -na (Swahili penda 'to love', pendana 'to love each other'; also applicative pendea 'to love for' and causative pendeza 'to please').
Word order
A subject–verb–object word order is quite widespread among today's Niger–Congo languages, but SOV is found in branches as divergent as Mande, Ijoid and Dogon. As a result, there has been quite some debate as to the basic word order of Niger–Congo.
Whereas Claudi (1993) argues for SVO on the basis of existing SVO > SOV grammaticalization paths (SOV > SVO is never found), Gensler (1997) points out that the notion of 'basic word order' is problematic as it excludes structures with, for example, auxiliaries. However, the structure SC-OC-VbStem (Subject concord, Object concord, Verb stem) found in the "verbal complex" of the SVO Bantu languages suggests an earlier SOV pattern (where the subject and object were at least represented by pronouns).
Noun phrases in most Niger–Congo languages are characteristically noun-initial, with adjectives, numerals, demonstratives and genitives all coming after the noun. The major exceptions are found in the western[17] areas where verb-final word order predominates and genitives precede nouns, though other modifiers still come afterwards. Degree words almost always follow adjectives, and except in verb-final languages adpositions are prepositional.
The verb-final languages of the Mende region have two quite unusual word order characteristics. Although verbs follow their direct objects, oblique adpositional phrases (like "in the house", "with timber") typically come after the verb,[17] creating a SOVX word order. Also noteworthy in these languages is the prevalence of internally headed and correlative relative clauses, in both of which the head occurs inside the relative clause rather than the main clause.
Major clades
The traditional branches and major languages of the Niger–Congo family are:[18]
- Kordofanian languages: spoken in southern central Sudan, around the Nuba Mountains (not a single family)
- ? Mande: spoken in West Africa; includes Bambara, the main language spoken in Mali, as well as Soninke, a language spoken mainly in Mali but also in Senegal and Mauritania. The evidence linking Mande to Niger–Congo is thin. Blench regards it as an early branch that diverged before the morphology characteristic of most of Niger–Congo developed, which Dimmendaal (2008) argues that for now it is best considered an independent family.
- ? Ijoid in Nigeria, including Ijo and Defaka.
- ? Dogon, spoken in Mali. The evidence linking Dogon to Niger–Congo is weak.
- Atlantic: includes Wolof, spoken in Senegal, and Fula, a language spoken across the Sahel. The validity of Atlantic as a genetic grouping is controversial.
- Kru: spoken in West Africa, include Bété, Nyabwa, and Dida.
- Senufo: spoken in Ivory Coast and Mali, with a geographical outlier in Ghana, and including Senari and Supyire.
- Gur languages, such as More in Burkina Faso
- Adamawa languages, such as Chamba Leko in Cameroon
- ? Ubangi languages, such as Sango in the Central African Republic. Olson (2006:165–167) demonstrated that the evidence linking Ubangian to Niger–Congo is weak, and Dimmendal (2008) went so far as to exclude Ubangian from Niger–Congo.[19]
- Kwa: includes Akan, spoken in Ghana.
- Volta–Niger (= West Benue–Congo), including:
- (East) Benue–Congo, including:
Some linguists consider the twenty or so Kordofanian languages to form part of the Niger–Congo family, whereas others consider them and Niger–Congo to form two separate branches of a Niger–Kordofanian language family, and yet others do not accept Kordofanian as a single group. Senufo has been placed traditionally within Gur, but is now usually considered an early offshoot from Atlantic–Congo.
However, Roger Blench believes that Adamawa, Ubangian, Kwa, Bantoid, and Bantu are not coherent groups.[20]
The Laal, Mpre, and Jalaa languages are often linked with Niger–Congo, but have yet to be conclusively classified.
Notes
- ^ a b Irene Thompson, “Niger-Congo Language Family”, ”aboutworldlanguages”, March 2015
- ^ “Niger-Congo Languages”, ”The Language Gulper”, March 2015
- ^ John Benjamins, “Historical Linguistics and the Comparative Study of African Languages”, ”John Benjamins Publishing Company”, March 2015
- ^ Williamson, Kay; Blench, Roger (2000). "Niger-Congo". In Bernd Heine; Derek Nurse (eds.). African Languages: An Introduction. Cambridge University Press. pp. 11–12.
- ^ a b c d e f Morton, Deborah. [ATR] Harmony in an Eleven Vowel Language. Ohio State University, 2012:70–71.
- ^ a b c d e Unseth, Carla. Vowel Harmony in Wolof. Graduate Institute of Applied Linguistics, 2009:2–3.
- ^ a b Bakovic, Eric. Harmony, Dominance and Control. Diss. Rutgers, The State University of New Jersey, 2000:ii.
- ^ "Clements, G. N. 1981. Akan vowel harmony: A non-linear analysis. Harvard Studies in Phonology 2.108–177."
- ^ a b Casali, Roderic F. "Nawuri ATR Harmony in Typological Perspective." Summer Institute of Linguistics, 2002:29. Journal of West African Languages 29.1 (2002).
- ^ "Anderson, C.G. 1999. ATR vowel harmony in Akposso. Studies in African Linguistics, 28(2):185–214."
- ^ "Archangeli, Diana, & Douglas Pulleyblank. 1994. Grounded Phonology (Current Studies in Linguistics, 25.) Cambridge: MIT Press."
- ^ Casali, Roderic F. "ATR Harmony in African Languages." Language and Linguistics Compass 2.3 (2008): 469–549.
- ^ Doneux, Jean L. 1975. Hypothèses pour la comparative des langues atlantiques. Africana Linguistica 6.41–129. Tervuren: Musée Royal de l’Afrique Centrale. (Re: proto-Atlantic), Williamson, Kay. 2000. Towards reconstructing Proto-Niger-Congo. Proceedings of the 2nd World Congress of African Linguistics, Leipzig 1997, ed. H. E. Wolff and O. Gensler, 49–70. Köln: Rüdiger Köppe. (Re: proto-Ijoid), Stewart, John M. Towards Volta-Congo Reconstruction: Rede. Leiden: Universitaire Pers Leiden, 1976., Casali, Roderic F. "On the Reduction of Vowel Systems in Volta-Congo." African Languages and Cultures 8.2 (1995: 109–121) (Re: proto-Volta-Conga)
- ^ Stewart, John M., 2002. The potential of Proto-Potou-Akanic-Bantu as a pilot Proto-Niger- Congo, and the reconstructions updated. Journal of African Languages and Linguistics 23: 197–224.
- ^ le Saout (1973) for an early overview, Stewart (1976) for a diachronic, Volta–Congo wide analysis, Capo (1981) for a synchronic analysis of nasality in Gbe (see Gbe languages: nasality), and Bole-Richard (1984, 1985) as cited in Williamson (1989) for similar reports on several Mande, Gur, Kru, Kwa, and Ubangi languages.)
- ^ As noted by Williamson (1989:24). The assumptions are from Ferguson's (1963) 'Assumptions about nasals' in Greenberg (ed.) Universals of Language, pp 50–60 as cited in Williamson art.cit.
- ^ a b Haspelmath, Martin; Dryer, Matthew S.; Gil, David and Comrie, Bernard (eds.) The World Atlas of Language Structures; pp 346–385. Oxford: Oxford University Press, 2005. ISBN 0-19-925591-1
- ^ Williamson & Blench (2000)
- ^ Dimmendaal (2008) states that Ubangian "probably constitutes an independent language family that cannot or can no longer be shown to be related to Niger–Congo (or any other family)."
- ^ "Niger-Congo: an alternative view" (PDF). Rogerblench.info. Retrieved 2012-12-29. "Roger Blench: Niger-Congo reconstruction". Rogerblench.info. Retrieved 2012-12-29.
Further reading
- Vic Webb (2001) African Voices: An Introduction to the Languages and Linguistics of Africa
- Bendor-Samuel, John & Rhonda L. Hartell (eds.) (1989) The Niger–Congo Languages – A classification and description of Africa's largest language family. Lanham, Maryland: University Press of America.
- Bennett, Patrick R. & Sterk, Jan P. (1977) 'South Central Niger–Congo: A reclassification'. Studies in African Linguistics, 8, 241–273.
- Blench, Roger (1995) 'Is Niger–Congo simply a branch of Nilo-Saharan?' In Proceedings: Fifth Nilo-Saharan Linguistics Colloquium, Nice, 1992, ed. R. Nicolai and F. Rottland, 83–130. Köln: Rüdiger Köppe.
- —— (2011) "Can Sino-Tibetan and Austroasiatic help us understand the evolution of Niger–Congo noun classes?",[1] CALL 41, Leiden
- —— (2011) "Should Kordofanian be split up?"[2], Nuba Hills Conference, Leiden
- Capo, Hounkpati B.C. (1981) 'Nasality in Gbe: A Synchronic Interpretation' Studies in African Linguistics, 12, 1, 1–43.
- Casali, Roderic F. (1995) 'On the Reduction of Vowel Systems in Volta–Congo', African Languages and Cultures, 8, 2, December, 109–121.
- Dimmendaal, Gerrit (2008). "Language Ecology and Linguistic Diversity on the African Continent". Language and Linguistics Compass. 2 (5): 840–858. doi:10.1111/j.1749-818X.2008.00085.x.
{{cite journal}}
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(help) - Greenberg, Joseph H. (1963) The Languages of Africa. Indiana University Press.
- Gregersen, Edgar A. (1972) 'Kongo-Saharan'. Journal of African Linguistics, 4, 46–56.
- Olson, Kenneth S. (2006) 'On Niger–Congo classification'. In The Bill question, ed. H. Aronson, D. Dyer, V. Friedman, D. Hristova and J. Sadock, 153–190. Bloomington, IN: Slavica.
- Saout, J. le (1973) 'Languages sans consonnes nasales', Annales de l Université d'Abidjan, H, 6, 1, 179–205.
- Stewart, John M. (1976) Towards Volta–Congo reconstruction: a comparative study of some languages of Black-Africa. (Inaugural speech, Leiden University) Leiden: Universitaire Pers Leiden.
- Stewart, John M. (2002) 'The potential of Proto-Potou-Akanic-Bantu as a pilot Proto-Niger–Congo, and the reconstructions updated', in Journal of African Languages and Linguistics, 23, 197–224.
- Williamson, Kay (1989) 'Niger–Congo overview', in Bendor-Samuel & Hartell (eds.) The Niger–Congo Languages, 3–45.
- Williamson, Kay & Blench, Roger (2000) 'Niger–Congo', in Heine, Bernd and Nurse, Derek (eds) African Languages – An Introduction. Cambridge: Cambridge University Press, pp. 11–42.