Proto-Bantu is the reconstructed common ancestor of the 550 or so Bantu languages which are spread across Central and Southern Africa. It is thought to have originally been spoken in West/Central Africa in the area of what is now Cameroon. Approximately 3000–4000 years ago, it split off from other Niger–Congo languages when the Bantu expansion began to the south and east. Two theories have been put forward about the way the languages expanded: one is that the Bantu-speaking people moved first to the Congo region and then a branch split off and moved to East Africa; the other (more likely) is that the two groups split from the beginning, one moving to the Congo region, and the other to East Africa.
Like other proto-languages, there is no record of Proto-Bantu. Its words and pronunciation have been reconstructed by linguists. From the common vocabulary which has been reconstructed on the basis of present-day Bantu languages, it appears that agriculture, fishing, and the use of boats were already known to the Bantu people before their expansion began, but iron-working was still unknown. This places the date of the start of the expansion somewhere between 3000 BC and 800 BC.
Doubts continue to be raised as to whether Proto-Bantu, as a unified language, actually existed in the time before the Bantu expansion, or whether, if we were to go back in time to that period we would find not a single language but a group of related dialects. One scholar, Roger Blench, writes: "The argument from comparative linguistics which links the highly diverse languages of zone A to a genuine reconstruction is non-existent. Most claimed proto-Bantu is either confined to particular subgroups, or is widely attested outside Bantu proper."
Proto-Bantu is generally reconstructed to have a relatively small set of sounds of 11 consonants and 7 vowels.
- Voiceless consonants *p, *t, *k were almost certainly articulated as simple plosives [p], [t], [k].
- Voiced consonants *b and *g may also have been fricatives [β] (or [v]) and [ɣ] in some environments.
- *d was a plosive [d] before a high vowel (*i, *u) and a lateral [l] before other vowels.
- *c and *j may have been plosives [c] and [ɟ], affricates [tʃ] and [dʒ] or even sibilants [s] and [z]. [j] is also possible for *j.
Consonant clusters did not occur except for the "pre-nasalised" consonants.
The so-called "pre-nasalised" consonants were sequences of a nasal and a following obstruent. They could occur anywhere a single consonant was permitted, including word-initially. Pre-nasalised voiceless consonants were rare, as most were voiced. The nasal's articulation adapted to the articulation of the following consonant so the nasal can be considered a single unspecified nasal phoneme (indicated as *N) which had four possible allophones. Conventionally, the labial pre-nasal is written *m while the others are written *n.
- *mb, *mp; phonemically *Nb, *Np
- *nd, *nt; phonemically *Nd, *Nt
- *nj, *nc; phonemically *Nj, *Nc (actually pronounced as *ɲj, *ɲc)
- *ng, *nk; phonemically *Ng, *Nk (actually pronounced as *ŋg, *ŋk)
The representation of the vowels may differ in particular with respect to the two "middle" levels of closedness. Most linguists write the "less closed" set as *ɪ and *ʊ. However, some prefer to denote them as *e and *o, with the more open set represented as *ɛ and *ɔ. Regardless of its representation, the third level (*e and *o in the table) was open-mid [ɛ] and [ɔ].
Syllables always ended in a vowel but could also begin with one. Vowels could also occasionally appear in a sequence but did not form diphthongs; two adjacent vowels were separate syllables. If two of the same vowel occurred together, that created a long vowel, but that was rare.
Proto-Bantu distinguished two tones, low and high. Each syllable had either a low or a high tone. A high tone is conventionally indicated with an acute accent (´), and a low tone is either indicated with a grave accent (`) or not marked at all.
Proto-Bantu, like its descendants, had an elaborate system of noun classes. Noun stems were prefixed with a noun prefix to specify their meaning. Other words that related or referred to that noun, such as adjectives and verbs, also received a prefix that matched the class of the noun ("agreement" or "concord").
Maho offers a broad characterization of five types of Bantu concordial systems. Languages descended from Proto-Bantu can be classified into each of the five types.
- Type A: Traditional, strictly formal
- Type B: Traditional with general animate concords
- Type C: Animacy-based SG/PL-marking
- Type D: SG/PL-marking only
- Type E: No concords at all
The following table gives a reconstruction of the system of nominal classes. Spellings have been normalised to use the ɪ and ʊ notations. Guthrie's original work uses y to describe the palatal semi-vowel, which has been normalised to use the j notation.
|2||*ba-||*ʋa-||*ba-||*ba-||*va-||*va-||*ba-||Plural of class 1|
|4||*mɪ-||*mi-||*mɪ-||*me-||*mɪ-||*mɪ-||*mɪ-||Plural of class 3|
|6||*ma-||*ma-||*ma-||*ma-||*ma-||*ma-||*ma-||Plural of class 5, liquids (mass nouns)|
|7||*kɪ-||*ki-||*kɪ-||*ke-||*kɪ-||*kɪ-||*kɪ-||Various, diminutives, manner/way/language|
|8||*pi-||*ʋɪ-||*bi-||*bi-||*ʋi-, *li- ("8x")||*ʋi-, *di-||*bi-||Plural of class 7|
|10||*thin-||*lɪ, ni-||*n-||*nj-||*li-nɪ-||*di-n-||*n-||Plural of class 9 and 11|
|12||*ka- (13)||*ka- (13)||*ka-||*ka-||*ka-||*ka-||*ka-||Diminutives|
|13||*tʊ- (12)||*tʊ- (12)||*tʊ-||*to-||*tʊ-||*tʊ-||*tʊ-||Plural of class 12|
|16||*pa-||*pa-||*pa-||*pa-||*pa-||*pa-||*pa-||Locatives (proximal, exact)|
|17||*kʊ-||*kʊ-||*ko-||*kʊ-||*kʊ-||*kʊ-||Locatives (distal, approximate)|
Wilhelm Bleek’s reconstruction consisted of sixteen noun prefixes. Carl Meinhof adapted Bleek’s prefixes, changing some phonological features and adding more prefixes, bringing the total number to 21. A. E. Meeussen reduced Meinhof’s reconstructed prefixes to 19, but added an additional locative prefix numbered 23. Malcolm Guthrie later reconstructed the same 19 classes as Meeussen, but removed locative prefix numbered 23.
Hendrikse and Poulos proposed a semantic continuum for Bantu noun classes. Numbers identifying noun classes in the table are referenced from the above table giving a reconstruction of nominal classes.
|Nouns||→||Adjective-like Nouns||→||Adverb-like Nouns||→||Verb-like Nouns|
|1/2, 3/4, 9/10||5/6, 7/8, 11||12/13, 19, 20, 21, 22||16, 17, 18, 23||14||15|
|Concreteness (five senses)||Attribution (two senses)||Spatial orientation (one sense)||Abstractness (no sense)|
This arrangement permits the classification of noun classes via nonlinguistic factors like perception and cognition. Hendrikse and Poulos have grouped singular and plural classes (such as classes 1 and 2) together, and created "hybrid positions" between the varying categories (such as the placement of class 14).
Noun class pairings
Classes 2, 4, 6, 8, 10, and 13 are generally accepted as being the plural forms of noun classes in Proto-Bantu. Classes 14 onward do not have a plural form defined as concretely as classes 1-13 do.
Meeussen proposed pairings of 1/2, 3/4, 5/6, 7/8, 9/10, 11/10, 12/13, 14/6, 15/6, and "probably" 19/13.
Maho combines pairings by De Wolf, Meeussen, and Guthrie, offering alternative pairings such as 3/10, 3/13, 9/4, 11/4, 12/4, 14/4, 14/10, 15/4, 19/4, and 19/10.
During the last hundred years, beginning with Carl Meinhof and his students, great efforts have been made to examine the vocabulary of the approximately 550 present day Bantu languages and to try to reconstruct the proto-forms from which they presumably came. Among other recent works is that by Bastin, Coupez, and Mann, which assembled comparative examples of 92 different words from all the 16 language zones established by Guthrie.
Although some words are found only in certain of the Guthrie zones, others are found in every zone. These include for example *mbʊa [HL] 'dog', *-lia 'eat', *ma-béele 'breasts', *i-kúpa 'bone', *i-jína 'name', *-genda 'walk', *mʊ-kíla 'tail', *njɪla 'path', and so on. (The asterisks show that these are reconstructed forms, indicating how the words are presumed to have been pronounced before the Bantu expansion began.)
Other vocabulary items tend to be found in either one or the other of the two main Bantu dialect groups, the Western group (mainly covering Guthrie zones A, B, C, H, K, L, R) or the Eastern group (covering zones D, E, F, G, M, N, P, and S). Words reconstructed for these two groups are known as "Proto-Bantu A" ("PB-A") and "Proto-Bantu B" ("PB-B") respectively, whereas those which extend over the whole Bantu area are known as "Proto-Bantu X" (or "PB-X").
Building on the work done by A. E. Meeussen in the 1960s, a publicly searchable database of all the Bantu vocabulary items which have been established or proposed so far is maintained by the Royal Museum for Central Africa at Tervuren in Belgium (see External links).
- Erhet & Posnansky, eds. (1982), Newman (1995)
- Dimmendaal, Gerrit J. (2011). Historical Linguistics and the Comparative Study of African Languages, pp. 337ff.
- Newman (1995), Shillington (2005)
- Vansina (1995) quoted by Schadeberg, T. C. in Nurse, D. & Philippson, G. (eds) (2006) The Bantu Languages, p. 160.
- Blench, Roger . Paper circulated before the Niger-Congo conference of September 2012.
- Hyman, Larry (2003). In Nurse, D. & Philippson, G. (eds) The Bantu Languages. pp. 42ff. 
- Derek Nurse, Gérard Philippson (eds) (2006) The Bantu Languages.
- Maho, J. F. (1999). A comparative study of Bantu noun classes.
- Guthrie, M. (1970). Collected Papers on Bantu Linguistics.
- Bastin, Yvonne, André Coupez, and Michael Mann (1999). Continuity and Divergence in the Bantu Languages: Perspectives from a Lexicostatistic Study. (Annales, 162.) Tervuren: Musée royal de l’Afrique Centrale. 225 pp.
- Schadeberg, T. C. in Nurse, D. & Philippson, G. (eds) (2006) The Bantu Languages, pp. 154ff.
- Bostoen & Bastin (2016), p. 4 (see External links).
- A. E. Meeussen "Bantu Grammatical Reconstructions". Africana Linguistica 3, 1967. pp. 79-121.
- "Bantu Lexical Reconstructions 3". Royal Museum for Central Africa, Tervuren. Searchable database of reconstructed Proto-Bantu words.
- Bostoen, Koen & Bastin, Yvonne (2016). "Bantu lexical reconstruction". Oxford Handbooks Online. An account of the history and main principles of reconstructing Proto-Bantu vocabulary.