Guthrie classification of Bantu languages

The 250 or so "Narrow Bantu languages" are conventionally divided up into geographic zones first proposed by Malcolm Guthrie (1967–1971). These were assigned letters A–S and divided into decades (groups A10, A20, etc.); individual languages were assigned unit numbers (A11, A12, etc.), and dialects further subdivided (A11a, A11b, etc.). This coding system has become the standard for identifying Bantu languages; it was a practical way to distinguish many ambiguously named languages before the introduction of ISO 639-3 coding, and it continues to be widely used. Only Guthrie's Zone S is (sometimes) considered to be a genealogical group. Since Guthrie's time a Zone J (made of languages formerly classified in groups D and E) has been set up as another possible genealogical group bordering the Great Lakes.
The list is first summarized, with links to articles on accepted groups of Bantu languages (bold decade headings). Following that is the complete 1948 list, as updated by Guthrie in 1971 and by J. F. Maho in 2009.
The list below reflects Guthrie as updated by Maho (2009). Not included in detail are the Northeast Bantu languages characterized by Dahl's Law, which is thought to be a genealogical group, cuts across the Guthrie system, and is covered at Northeast Bantu. Other groups with dedicated articles, such as Southern Bantu (Zone S) are also only summarized here, so that the initial listing is only a summary and an index for other articles.
Ethnologue made multiple changes to Guthrie in an attempt to make the classification more historically accurate. However, the changes are inconsistent, and Ethnologue has not been followed here, though it is publicly available online. Thus a code may mean different things depending on whether Guthrie or SIL is being followed. (See link below for the SIL code assignments.) The updates in Maho (2009), on the other hand, are designed to be compatible with the original values of the codes.
Bantu has long been divided into Northwest Bantu (Forest Bantu) and Central Bantu (Savanna Bantu) branches based upon tone patterns, but there is little agreement as to which Guthrie zones (or which parts of zones) should be in either, the dichotomy is dubious, and they have not been followed here.
Accepted genealogical groups within the Guthrie zones are boldfaced.
S Cameroon, Equatorial Guinea, N Gabon
Zone A is sometimes considered Forest Bantu.
Guthrie's A60 and part of his A40 have been removed to the Southern Bantoid Mbam languages. Sawabantu may include some of the A10 languages apart from Manenguba, whereas Bube may belong in Mbam.
Southern Bantoid Jarawan was assigned to Zone A by Gerhardt (1982) and Blench (ms 2006, 2011), specifically to A60, within Mbam.
According to several scholars, including Blench, there can be no coherent concept of Bantu as long as many of the Zone A and perhaps Zone B languages are included.
S Gabon, W Congo, W DR-Congo
Zone B is sometimes considered Forest Bantu.
B10–30 may belong together as Kele–Tsogo, B40 with Kongo–Yaka (H), and B50–70 with H24 Songo as Teke–Mbede.
NW DR-Congo, N Congo
Zone C is sometimes considered Forest Bantu, sometimes Savanna Bantu.
There are proposals for three larger clades, Mboshi–Buja covering C10–20 and C37+41, and Bangi–Tetela covering C30 with C50–80 (Motingea 1996), and C40a together with D20–30 in Boan.
NE DR-Congo
D10, D30, and some of D20 and D40 are sometimes considered Forest Bantu, the others Savanna Bantu.
Most of D40–60 has been moved to Great Lakes Bantu languages. Lengola, Bodo, and Nyali may belong together as Lebonya, and Beeke in Boan.
Kenya, apart from Swahili
The languages of Zone E have been reassigned: E10–E40 to Great Lakes Bantu languages; E50 Kikuyu–Kamba (Central Kenya Bantu) and E60 Chaga–Taita to Northeast Bantu; E70 Nyika to Northeast Bantu, mostly in Sabaki.
W & C Tanzania.
Much of F20 and F30, including the major language Sukuma, have been reclassified as Northeast Bantu, with Bungu to Rukwa and Sumbwa as Great Lakes. Mbugwe–Rangi, however, form a valid node by themselves.
Isanzu is sometimes classified as F30, as a variety of Nilamba, and sometimes thought to be a remnant of the Bantu languages spoken in the area before F-zone languages arrived.
E Tanzania, Comoros
The languages of Zone G have been reclassified, G60 Bene–Kinga to Northeast Bantu, and the other branches more specifically to Northeast Coast Bantu languages.
NW Angola, W Congo
H10 and H40 are sometimes considered Forest Bantu, the others Savanna Bantu.
H10 Kunyi, Suundi, and Vili have been split between B40 and L10. H40 is split between H30 and L10.
Kongo–Yaka may form a family, perhaps with B40 Sira.
Uganda, Rwanda–Burundi, near lakes Kivu & Victoria
E Angola, W Zambia
K20 Lozi is now classified as Southern Bantu, specifically Sotho-Tswana. Some K30 languages have been reclassified as Kavango, but Luyana is an independent lineage. K40 Subiya–Totela has been reclassified as Botatwe, apart from Mbukushu, which appears to be an independent lineage.
S DR-Congo, C Zambia
L20 Songe (apart perhaps from Lwalu), L30 Luba, L40 Kaonde, and L60 Nkoya have been grouped as Luban.
E Zambia, SE DR-Congo
Sabi–Bobatwe may be related.
Malawi and surrounding areas, C Mozambique, N. Zimbabwe, W. Zambia
N10 Manda has been classified as Rufiji–Ruvuma, and the N20 Tumbuka 'dialect' Senga as Sabi.
NE Mozambique, SE Tanzania
P10 Matuumbi and P20 Yao have been classified as Rufiji–Ruvuma, P15 Mbunga as Kilombero, P30 Makhuwa as Southern Bantu.
SW Angola, N Namibia, N Botswana
R20 Ovambo, R30 Herero, and R10 apart from Umbundu have been grouped together as Southwest Bantu. Yeyi forms its own lineage.
South Africa, Botswana, Zimbabwe, S. Mozambique.
Following is the original list from Guthrie (1948), with all numerical assignments, as updated by Guthrie himself (1971) and J.F. Maho (2009). The groups are geographic, and do not necessarily imply a relationship between the languages within them. Words in parentheses are added for disambiguation. Numbers in brackets are changes made in Maho (2009); languages in brackets were added by Maho (2009). Languages of the proposed Zone J are included among zones D and E.
§: These languages do not have separate articles, though they might warrant them.
Besides the languages added within the existing framework above, Maho appends several creoles, pidgins, and mixed languages:
§: These languages did not have separate articles at the last review by a Wikipedia editor.