[b]→[m]Certainty: 5/5Commonality: 3/5
Voiced bilabial plosive to Bilabial nasal
The shift from the voiced bilabial stop [b] to the bilabial nasal [m] is a process of nasalization. It typically occurs through regressive nasal assimilation, where the stop acquires the nasal airflow of a following sound.
Phonetic Effects
Nasalization, Assimilation, Meinhof's Law
Language Examples
n-bumba→mmumba— Ganda Law (Meinhof's Law): A voiced stop becomes a nasal when followed by a prenasalized consonant in the next syllable.
ᵐb (prenasalized voiced bilabial stop)→m— In Kalam and related Trans-New Guinea languages, the Proto-TNG prenasalized stop *ᵐb simplifies to a plain nasal [m] in certain daughter languages. The voiced stops represented in Kalam orthography (/b/, /d/, /g/) correspond historically to prenasalized stops reconstructed for Proto-Trans-New Guinea.
Proto-TNG *ᵐb (word-final)→m— In Enga (Engan branch, Trans-New Guinea), word-final prenasalized stops regularly simplify to their nasal component. The bilabial prenasalized stop *ᵐb yields final [m], a pervasive pattern in Engan and other Highlands TNG languages where syllable-final consonant inventories are reduced to sonorants.
Related Transformations
More Nasalization Shifts
Sources & References
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