A record of where the voiceless bilabial plosive went to die.
However language began, one thing is certain — it immediately began to change, and has been changing ever since.
David Crystal · 2007
時有古今。
地有南北。
字有更革。
音有轉移。
陳第 · 1606/p/ — the voiceless bilabial plosive — is one of the most widespread phonemes in human language. And yet it is absent from roughly 10%
of the world's languages, and in many others it has weakened, shifted, or vanished under specific
phonological conditions.
This site records those losses. The diagram below is a phonological flow chart — each ribbon is one lineage of /p/ over time. A ribbon's color is the phoneme as it's articulated at that year (amber for /p/, blue for /f/, violet for /ɸ/, green for /h/, teal for /ç/, rose for /w/, grey for ∅). When a single /p/ splits into multiple environments, ribbons fork. When the color shifts mid-flow, that's a sound change in progress. Pre-evidence sections fade in from transparent — we know /p/ was there, but its exact form is extrapolated. Dots are attestation points. The ribbons are grouped by language family so you can see, e.g., the fates of Indo-European *p side by side.
Status: Lost in Proto-Celtic
One of the showpiece sound losses of Indo-European studies. PIE *p disappeared early in the Celtic branch, before Proto-Celtic split into its daughters. The classic cognates expose it:
PIE: *pPCelt: ∅ e.g. *ph₂tḗr → OIr. athair/p/ later re-entered Celtic from kw in the P-Celtic branch (Welsh pedwar "four" < PIE *kʷetwores), but inherited PIE *p never came back.
Status: Lost
Proto-Semitic had *p, retained in many sister languages — Hebrew shows it as [p]~[f] allophony, Akkadian had /p/. Arabic merged it with /f/ before the historical record:
PSem: *pArabic: f Status: Partially alive
Old Chinese had *p. In late Middle Chinese the labial initials split — 輕唇音 (light labials) and 重唇音 (heavy labials) — and *p underwent labiodentalization before specific medial-vowel combinations:
MC: pMand.: p elsewhere e.g. 北 běiMC: pMand.: f _jɨ, _ju, _jo e.g. 飛 fēi,
風 fēngModern Mandarin keeps /p/ in plenty of words, but a large slice of the inherited vocabulary exited via /f/.
Status: Conditioned loss — /p/ survived in narrow environments and was later reinforced by loans.
The most thoroughly documented case. Old Japanese /p/ weakened to /ɸ/ in most positions by the late Heian period, then split further by the following vowel. It was never eliminated outright — the {Q, N}_V branch carried /p/ through unchanged — and from the 16th century onward loanwords added /p/ back in unrestricted positions.
OJ: pMJ: ɸ V_V MJ: ɸmJ: h _{a, o, e}MJ: ɸmJ: ç _iMJ: ɸmJ: ɸ _u (marginal)OJ: pmJ: p {Q, N}_V e.g. 切符 kippu, 散歩 sanpo/p/ then re-entered unrestricted positions wholesale: first via Portuguese loans (1543: pan, tabako), then Dutch, and at scale through modern English loans — reinforcing a phoneme that had narrowly survived the Heian-era weakening.