The insertion of a nasal between a root's first vowel and the following consonant is seen in a number of roots:
*dàì(m)pú 'long'
*í(n)gùà 'thorn'
*í(n)gu 'hear'
*í(n)sò 'eye'
*ì(n)sɪ̀ 'pestle'
*ìy 'come' ~ *ìnz 'come'
*íyɪ̀ 'water' ~ *ínzɪ̀ 'water'
*ó(n)t 'warm oneself'
*kòsʊ̀è ‘rat’ ~ *kònzò 'domestic rat'
*kó(n)di 'light fire'
*kʊ́pá 'tick' ~ *kʊmba 'house tick'
*pádá 11 ‘baldness’ ~ *pánzà 'baldness'
*pá(m)pat ‘touch, grope’
*tá(m)bɪ̀ 'branch'
*tu(n)tu 'small heap'
This phenomenon is not regular in any obvious way, but it involves enough roots to require at least a partial explanation. Further study is required, but at this stage, it can be noted that:
—nasal insertion is better attested in Eastern Bantu, but this may merely be a matter of documentation
—nasal insertion or variation seems sometimes connected with the vowel i (see Wills 2025:10)
—nasal insertion may arise as a variant that saves the following consonant from sound changes, e.g. *g is regularly lost in South Bantu, but *ng is not. Cf. *-nòg- ‘pick (e.g. beans)’ ~ Central Shonic -nónga ‘pick up; find’.
—nasal insertion occurred not only at early or intermediate stages of Bantu history, but also recently as can be seen from examples in modern languages, e.g. Zezuru rwàtáhwì & rwàtámbwi 11 'hymen' (once again *bʊ > hu, but *mbʊ is stable); Zulu -sha(n)yéla & -shanéla ‘sweep’; Ikorovere dialect of Makhuwa: w-ivva, w-inva, w-iiva 'kill' (see T.C. Schadeberg 1999).
*dàì(m)pú 'long'
*í(n)gùà 'thorn'
*í(n)gu 'hear'
*í(n)sò 'eye'
*ì(n)sɪ̀ 'pestle'
*ìy 'come' ~ *ìnz 'come'
*íyɪ̀ 'water' ~ *ínzɪ̀ 'water'
*ó(n)t 'warm oneself'
*kòsʊ̀è ‘rat’ ~ *kònzò 'domestic rat'
*kó(n)di 'light fire'
*kʊ́pá 'tick' ~ *kʊmba 'house tick'
*pádá 11 ‘baldness’ ~ *pánzà 'baldness'
*pá(m)pat ‘touch, grope’
*tá(m)bɪ̀ 'branch'
*tu(n)tu 'small heap'
This phenomenon is not regular in any obvious way, but it involves enough roots to require at least a partial explanation. Further study is required, but at this stage, it can be noted that:
—nasal insertion is better attested in Eastern Bantu, but this may merely be a matter of documentation
—nasal insertion or variation seems sometimes connected with the vowel i (see Wills 2025:10)
—nasal insertion may arise as a variant that saves the following consonant from sound changes, e.g. *g is regularly lost in South Bantu, but *ng is not. Cf. *-nòg- ‘pick (e.g. beans)’ ~ Central Shonic -nónga ‘pick up; find’.
—nasal insertion occurred not only at early or intermediate stages of Bantu history, but also recently as can be seen from examples in modern languages, e.g. Zezuru rwàtáhwì & rwàtámbwi 11 'hymen' (once again *bʊ > hu, but *mbʊ is stable); Zulu -sha(n)yéla & -shanéla ‘sweep’; Ikorovere dialect of Makhuwa: w-ivva, w-inva, w-iiva 'kill' (see T.C. Schadeberg 1999).