Begadkefat (also begedkefet) is the phenomenon of lenition affecting the non-emphatic stop consonants of Biblical Hebrew and Aramaic when they are preceded by a vowel and not geminated. The name is also given to similar cases of spirantization of post-vocalic plosives in other languages; for instance, in the Berber language of Djerba.^[1] Celtic languages have a similar system.

The name of the phenomenon is made up of these six consonants, mixed with haphazard vowels for the sake of pronunciation: BeGaDKePaT. The Hebrew term בֶּגֶ״ד כֶּפֶ״ת‎ (Modern Hebrew /ˌbeɡedˈkefet/) denotes the letters themselves (rather than the phenomenon of spirantization). If a beged-kephat is at the beginning of a word, and is preceded by a word ending in an open syllable, then there is no dagesh. Begedkefet spirantization developed sometime during the lifetime of Biblical Hebrew under the influence of Aramaic.^[2] Its time of emergence can be found by noting that the Old Aramaic phonemes /θ/, /ð/ disappeared in the 7th century BC.^[3] During this period all six plosive / fricative pairs were allophonic.

In Modern Hebrew, Sephardi Hebrew, and most forms of Mizrahi Hebrew, three of the six letters, ב‎ (bet), כ‎ (kaf) and פ‎ (pe) each still denotes a stop–fricative variant pair; however, in Modern Hebrew these variants are no longer purely allophonic (see below). Although orthographic variants of ג‎ (gimel), ד‎ (dalet) and ת‎ (tav) still exist, these letters' pronunciation always remains acoustically and phonologically indistinguishable.^{[note 1]}

In Ashkenazi Hebrew and in Yiddish borrowings from Ashkenazi Hebrew, ת‎ without dagesh still denotes a fricative variant [s] (under the influence of Judeo-German, aka Yiddish) which diverged from Biblical/Mishnaic [θ].

The only extant Hebrew pronunciation tradition to preserve and distinguish all begadkefat letters is Yemenite Hebrew; however, in Yemenite Hebrew the sound of gimel with dagesh is a voiced palato-alveolar affricate [d͡ʒ] (under the influence of Judeo-Yemeni Arabic), which diverged from Biblical/Mishnaic [ɡ].

Orthography

The phenomenon is attributed to the following allophonic consonants:

In Hebrew writing with niqqud, a dot in the center of one of these letters, called dagesh ( ּ ), marks the plosive articulation:

• at the beginning of a word^{[note 2]} or after a consonant (in which cases it is termed "dagesh qal"^{[note 3]}),
• when the sound is – or was historically – geminated (in which case it is termed "dagesh ẖazaq", a mark for historical gemination in most other consonants of the language as well), and
• in some modern Hebrew words independently of these conditions (see below).

A line (similar to a macron) placed above it, called "rafe" ( ֿ ), marks in Yiddish (and rarely in Hebrew) the fricative articulation.

In Modern Hebrew

As mentioned above, the fricative variants of [ɡ], [d] and [t] no longer exist in modern Hebrew. (However, Hebrew does have the guttural R consonant /ʁ/ which is the voiced counterpart of /χ/ and sounds similar to Mizrahi Hebrew's fricative variant of [ɡ] ḡimel as well as Arabic's غ ġayn, both of which are [ɣ~ʁ]. Modern Hebrew ר resh can still sporadically be found standing in for this phoneme, for example in the Hebrew rendering of Raleb (Ghaleb) Majadele's name.) The three remaining pairs /b/~/v/, /k/~/χ/, and /p/~/f/ still sometimes alternate, as demonstrated in inflections of many roots in which the roots' meaning is retained despite variation of begedkefet letters' manner of articulation, e.g.,

however, in Modern Hebrew, stop and fricative variants of ב‎‏, כ‎ and פ‎ are distinct phonemes, and there are minimal pairs:

and consider, e.g.:

This phonemic divergence is due to a number of factors, amongst others:

• due to loss of consonant gemination in modern Hebrew, which formerly distinguished the stop members of the pairs from the fricatives when intervocalic – e.g. in the inflections:

• קפץ ← קיפץ‎	/kaˈfats/ → /kiˈpets/, historically /kipˈpets/	("jumped" → "hopped"),
• שבר ← שיבר‎	/ʃaˈvar/ → /ʃiˈber/, historically /ʃibˈber/	("broke" → "shattered"),
• שכן ← שיכן‎	/ʃaˈχan/ → /ʃiˈken/, historically /ʃikˈken/	("resided" → "housed"),

• due to the introduction, through foreign borrowings, of:

 • syllable-initial /f/ (e.g. פברק‎ /fibˈʁek/ "fabricated"),

 • non-syllable-initial /p/ (e.g. הפנט‎ /hipˈnet/ "hypnotized")

 • non-syllable-initial /b/ (e.g. פברק‎ /fibˈʁek/ "fabricated"), ג׳וֹבּ /dʒob/ "job", קוּבּ‎ /kub/ "cubic meter", פָּאבּ‎ /pab/ "pub").

Even aside from borrowings or lost gemination, common Israeli pronunciation sometimes violates the original phonological principle "stop variant after a consonant; fricative after a vowel", although this principle is still prescribed as standard by the Academy of the Hebrew Language, e.g.:

• The words מעבורת‎ (ferry) and מעברות‎ (refugee absorption camps), whose respective prescribed pronunciation is /maʕˈboʁet/ and /maʕbaˈʁot/, are commonly pronounced /ma.aˈboʁet/ and /ma.abaˈʁot/, replacing the consonant (/ʕ/) with a vowel (/a/), but still preferring the stop variant /b/ to its fricative counterpoint /v/.
• Similarly, the words העפלה‎ (Aliyah Bet, called the Ha'apala which designates the covert Jewish immigration to British Palestine, 1934–1948) and מעפילים‎ (the immigrants of this immigration), whose respective prescribed pronunciation is /haʕpaˈla/ and /maʕpiˈlim/, are commonly pronounced /ha.apaˈla/ and /ma.apiˈlim/, again replacing the consonant (/ʕ/) with the vowel (/a/), but still preferring the stop /p/ to the fricative /f/.
• Conversely, words like להכחיש‎ (to deny) or מכחול‎ (paintbrush), whose respective prescribed pronunciation is /lehaχˈħiʃ/ and /miχˈħol/, are commonly pronounced /lehakˈχiʃ/ and /mikˈχol/, preferring the stop /k/ to the fricative /χ/, although following vowels (respectively /a/ and /i/), due to the shifting of the original semitic pronunciation of the letter ח‎ (heth) from /ħ/ to /χ/, rendering it identical to common Israeli pronunciation of the fricative variant of the letter כ‎.