Betacism
In historical linguistics, betacism is a sound change in which and are confused. The final result of the process can be either /b/ → or /v/ → . Betacism is a fairly common phenomenon; it has taken place in Greek, Hebrew, and several Romance languages.
Greek
In Classical Greek, the letter beta ⟨β⟩ denoted. As a result of betacism, it has come to denote in Modern Greek, a process which probably began during the Koine Greek period, approximately in the 1st century CE, along with the spirantization of the sounds represented by the letters delta. Modern Greek uses the digraph ⟨μπ⟩ to represent. Indeed, this is the origin of the word betacism.Romance languages
Perhaps the best known examples of betacism are those of the Romance languages; the earliest known in Latin dating to the 3rd century CE. The results of the shift are most widespread in the Western Romance languages, especially Spanish, in which the letters ⟨b⟩ and ⟨v⟩ are now both pronounced except phrase-initially and after a nasal consonant, when they are pronounced ; the two sounds are now allophones. Betacism is one of the main features in which Galician and northern Portuguese diverge from central and southern Portuguese. In Catalan, betacism features in many dialects, but not in central and southern Valencian or the Balearic dialect. In Occitan language, betacism is common in Gascon, Languedocien and Auvergnat dialects. Other Iberian languages with betacism are Astur-Leonese and Aragonese.Another example of betacism is in Neapolitan, or in Central Italian which uses ⟨v⟩ to denote betacism-produced, such that Latin bucca corresponds to Neapolitan vocca and to Maceratese vocca, Latin arborem to arvero or arvulo, and barba to Neapolitan varva and Maceratese varba.
Betacism in Latin
A famous medieval Latin saying states:The saying is a pun referring to the fact that the Iberians would generally pronounce the letter v the same as b instead of or . In Latin, the words vīvĕre and bĭbĕre are distinguished by the use of the letters v and b, thus creating a point of confusion in the Iberian pronunciation. Note however that the words were also distinguished by prosody, and the modern Spanish forms are vivir and beber.