Editing Vietnamese language (section)

=== Lenition of medial consonants ===
As noted above, Proto-Vietic had [[sesquisyllabic]] words with an initial [[minor syllable]] (in addition to, and independent of, initial clusters in the main syllable). When a minor syllable occurred, the main syllable's initial consonant was [[intervocalic]] and as a result suffered [[lenition]], becoming a voiced fricative.{{sfn|Ferlus|1992|p=113}} These fricatives were not present in Proto-Viet–Muong, as indicated by their absence in [[Muong language|Mường]], but were present in Vietnamese until the 15th or 16th centuries.{{sfn|Ferlus|1992|p=119}} Subsequent loss of the minor-syllable prefixes phonemicized the fricatives. Ferlus 1992 proposes that originally there were both voiced and voiceless fricatives, corresponding to original voiced or voiceless stops,{{sfn|Ferlus|1992}} but Ferlus 2009 appears to have abandoned that hypothesis, suggesting that stops were softened and voiced at approximately the same time, according to the following pattern:{{sfn|Ferlus|2009|p=96}}
*{{IPA|*p, *b}} > {{IPA|/β/}} > ''v''. In [[Middle Vietnamese]], the outcome of these sounds was written with a hooked ''b'' (ꞗ), representing a {{IPA|/β/}} that was still distinct from ''v'' (then pronounced {{IPA|/w/}}).
*{{IPA|*t, *d}} > {{IPA|/ð/}} > ''d''
*{{IPA|*c, *ɟ, *tʃ}} > {{IPA|/ʝ/}} > ''gi''
*{{IPA|*k, *ɡ}} > {{IPA|/ɣ/}} > ''g/gh''
*{{IPA|*s}} > {{IPA|/r̝/}} > ''r''