Peust, Carsten: Egyptian phonology: an introduction to the phonology of a dead language (Göttingen, 1999)

If a consonant is lost as the first component of a posttonic cluster, the stressed vowel may
be lengthened. The explanation seems to be that there was metathesis between the
second and the third consonants in such words, which then experienced the development
described above:

rri.t ('rVrVjtV) "sow" (> 'rijVrtV) > spdApe /'ra:re/

• shit fsahVftV) "to bring down" (> saSVhtV) > sCOC^e /'sdIW "to remove"
The retention of -r- in pdApe also presupposes a form (*'rijVrtV) (US' § 3.14-3.3).
If the second component of the cluster is a glide, there is as a rule no lengthening:

• mniw ('mVnViwV) "herdsman" > sJt&.H£ /'mano/

• hfiw ('hafVJwV) "serpent" > sooq /'haf/

• thi.w ('tahViwV) "to be drunk (stative)" > sT&2_e /'tahg/

If a consonant (apart from <c>) is lost in another position, there is no lengthening:

• ipd ('SapdV) "bird" > KOBT /'opty
ir.t ('iirtV) "to do" > seipe /'ire/

• wlh (WhV) "to look for" > sWTCOUJ /'woj/

• pM CpahJV) "to break" > sn(02 /'poh/

If <c> follows anywhere in the word after the stressed vowel, the stressed vowel is
lengthened:

• mn'.t ('manVW) "nurse" > sAOONG /'m3:na/

• h'-f ('ha'fV) "his body" > ^(fluXf /'ho:f/

• Yd ('sa'dV) "to cut" > spiXuT /'Jo:t/

• dbc ('tubcV) "finger" > STHHB£ /'te:Ba/

Several scholars (e.g. Vergote 1973/83: lb, § 36; Loprieno 1995: 44f.) explained this by a
metathesis which brought <c> closer to the stressed vowel. Perhaps this assumption is not
necessary, though. Vowel length is a suprasegmental phenomenon which can be realized
on the stressed vowel in a word even if it is motivated by a process at a different position.

Only when preceding the stressed vowel, <S does not cause lenghthening:
w'b (w[V]"ab) "to be clean" > ^OffOn /'wap/

Long vowels are frequently generalized through analogy (cf. Vycichl 1990: 198^):
bin ('bajnV) "bad (masculine)" t ^OXOM /'Bo:n/
bin.t ('bajVntV) "bad (feminine)" = '■BOONe /'pj:na/

• 5j/('sajfV) "to pollute" t KWS^ /'so:f/

• sif.w ('sajVfwV) stative of the same verb = HlOOq /'sD:f/

The plural forms of nouns are frequently characterized by a long vowel in Coptic. In
certain cases, this can be explained by the regular sound development rules, e.g.:

• ~s?s (safeV) "bedouin" > HtJCOC /'Jos/

• h's.w ('saWswV) "bedouins" > sUJOOC /'J3;s/

From such cases, vowel length was extended to plural forms of other nouns such as:

a36