[b]→[w]Certainty: 5/5Commonality: 4/5
Voiced bilabial plosive to Voiced labio-velar approximant
The shift from the voiced bilabial stop [b] to the voiced labio-velar approximant [w] is a common form of lenition, particularly in intervocalic positions where the stop closure weakens into a glide.
Phonetic Effects
Lenition, Vocalization
Language Examples
subir [b]→[suβir] / [suwir]— Intervocalic /b/ spirantizes to [β], which often approaches a glide [w] in rapid or relaxed speech.
Old Persian naiba- [b]→Middle Persian nēw [w]— Voiced stops after vowels became semivowels in Middle Persian: /b/ → /w/. Old Persian naiba- 'beautiful' became Middle Persian nēw. This lenition process began in the Arsacid period (before 3rd c. CE) and was complete in Sassanid Middle Persian.
Old Persian asabāra- [b] (horseman)→Middle Persian asvār [w]— Intervocalic /b/ → /w/; the form shows systematic b→w weakening in the postvocalic environment, characteristic of Middle Iranian lenition.
Old Iranian /b/ in various positions→Pashto [w] ~ [b]— Eastern Iranian, including Pashto, shows widespread spirantization of voiced stops. Old Iranian /b/ is reflected as [w] in many Pashto forms, continuing the general Eastern Iranian tendency toward lenition of voiced stops in all positions.
Related Transformations
More Romance Shifts
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