For instance, the development from the Latin [d] in HORDEUM[b] to the Italian [d͡z] in orzo is referred to as 'palatalization', despite the resulting [d͡z] not being a palatal sound, because intermediate stages like *[dʲ], *[d͡zʲ] may be inferred.
This has been argued on the grounds that languages like Romanian show the same outcomes for consonants followed by primary /j/ (from Late Latin), secondary /j/ (from later diphthongization), and the vowel /i/.
[6] Evidence of the palatalization of /tj kj/ appears as early as the 2nd–3rd centuries AD in the form of spelling mistakes interchanging ⟨ti⟩ and ⟨ci⟩ before a following vowel, as in ⟨TRIBUNITIAE⟩ for TRIBUNICIAE.
[7] The evidence includes inscriptional use of ⟨tsi⟩ or ⟨tz⟩ in place of ⟨ti⟩[8] and commentary by grammarians from the late 4th century onwards about the pronunciation of words spelled with ⟨ti⟩ + vowel.
Examples include faqe 'cheek' < FACIEM 'face'; kumerq 'toll, duty' < COMMERCIUM 'trade'; pus 'well, fountain' < PUTEUM 'well'; and mars 'March' < MARTIUM 'March'.
[13] Procopius, writing in Greek circa 553-555, uses the spellings Μουτζιανικάστελλον (Moutzianikástellon) for MUCIANI CASTELLUM and Λούτζολο (Loútzolo) for LUCIOLUM (De Aedificiis 4.4.3), which suggests that Latin /kj/ had developed to an affricate.
[6] According to one view, the regular outcome of /tj kj/ was [t͡s] before [a] or word-final [o u], as in înălța, județ < *INALTIARE, IUDICIUM; and [t͡ʃ] before non-final [o u], as in măciucă, urcior < MATTEUCA, URCEOLUS.
[3] The outcomes in many Romance languages are often explained by reconstructing a stage where /dj ɡj/ in general (as well as /ɡ/ before a front vowel) merged with /j/[31] which then underwent fortition[32] (especially at the start of a word or morpheme), often yielding an affricate like [d͡ʒ].
[34] Initial /j/ appears to have remained a palatal glide in Southern Italian, some dialects of Sardinian, and (in some contexts) Castilian,[34] which suggests that its fortition to an affricate or fricative may not been complete in Late Latin or Proto-Romance.
However, it is possible that Southern Italian and Castilian did not conserve the original value of Latin /j-/ but rather redeveloped the glide via later lenition (note that intervocalic /ɡj/ shows the same outcome).
[58] The Latin geminate -NN- seems to have developed likewise to [ɲ] before [i] (the only clear example is ANNI > Old Romanian ai,[59] later replaced by the analogical plural ani[6]), whereas originally singleton -N- remained before [i] (as in VENIRE > veni, CANI > câini), which Barbato interprets as a sign that /nj/ was previously geminated (although not palatalized until the original length contrast between -NN- and -N- had been replaced with a fortis-lenis contrast).
[6] /rj/ survives as a consonant cluster in Sardinian, as in CORIUM 'leather' > Nuorese [ˈkorju], Logudorese [ˈkord͡zu], and Campidanese [ˈkord͡ʒu];[42] and also some varieties of southern Corsican, as in AREAM > [ˈarɟa].
[81] Per Recasens, such cases of asymmetrical development may be the result of phonetic factors that make palatalization less favored for voiced compared to voiceless consonants.
[82] The sequence /rsj/ could have the same outcome, as in Tuscan [roveʃˈʃaːre] < *REVERSIARE;[77] compare the development of RS to [ss] in DORSUM > Italian dosso.
In Italian, intervocalic [pj βj mj] show gemination of the labial consonant, resulting in [ppj bbj mmj].
[84] Examples include SAPIAT > [ˈsappja],[52] RABIAM > rabbia[84] [ˈrabbja],[52] HABEAT > abbia, CAVEAM > gabbia, VINDEMIAM > vendemmia.
[88] The Portuguese metathesis of labial + /j/ sequences occurred late enough to affect some cases of secondary [j] that developed after lenition of a following intervocalic consonant (as in LIMPIDUM > *[ˈlim.pjo] > limpho 'clean' and COMEDO > *[ˈko.mjo] > coimo 'I eat').
[91][l] Proto-Romanian shows the development of a diphthongal offglide after a stressed vowel followed by an original sequence of labial consonant + palatal glide, as illustrated by *scupio > Romanian scuip, HABEAT > aibă, and DIFFAMIAM > defaimă.
[103] In Romanian, unlike most Romance languages, palatalization occurred after the loss of the [w] in sequences of [kw] or [ɡw] + front vowel, hence the affricates in sânge, acel < SANGUEM, *ECCUM ILLUM.
[105] The Vegliote dialect of Dalmatian showed palatalization of /k/ to [t͡ʃ] before /i/, but this is argued to be an separate internal innovation rather than an inherited trait in common with other Romance varieties.
[106] Epigraphic evidence indicates that in the Latin of the Late Empire onwards, intervocalic /ɡ/ may have already been lost in some words where it occurred between non-back vowels,[107] for example in viginti, frigidus, digitus[107] or legit, sagitta.
In Western Romance, intervocalic Latin /k/ before a front vowel was affected by both palatalization and voicing[48] and so generally had an outcome distinct from that of initial or post-consonantal /k/ before /i e ɛ/.
This apparently predated the general monophthongization of Latin AU to French o, as it affected words like CAUSAM > chose and GAUDIA > joie.
[137] Aside from Gallo-Romance, palatalization of /ka ɡa/ is also found in Rhaeto-Romance[q] and, in widely scattered traces, across the dialects of northern Italy (Gallo-Italic and Venetian).
The outcomes of SANCTUM 'holy' include Occitan sanch, French saint; Catalan sant, Italian-Portuguese-Spanish santo; and Old Romanian sămtu (modern sânt).
This probably began with /l/ allophonically turning to [ʎ] after a velar consonant;[165] the resulting system *[pl bl fl kʎ ɡʎ] underlies Balkan Romance, northern Abruzzese, old Gallo-Italic, and old Venetian.
Traditionally the latter have been blamed on borrowing or some form of 'learned' influence from Latin,[170] but it has also been suggested that the discrepancy may have to do with lexical frequency, perhaps alongside factors like dissimilation or avoidance of homonymy.
[172][z] The earliest evidence for the Spanish merger of palatalized initial /pl fl kl/ to one sound is found in eleventh-century documents with forms like ⟨flosa⟩ for CLAUSA, ⟨flano⟩ for PLANO, and ⟨aflamaront⟩[173] for ADCLAMAVERUNT.
[185] The earliest evidence for the palatalization of /l-/ is found in tenth-century documents from the Kingdom of León, which show forms like ⟨lliueram⟩ and ⟨llexastis⟩[186] for LIBRAM and LAXAVISTIS.
In Italian such alternations occur not only in verbs but also nouns, since velar consonants often remain unpalatalized before the masculine plural ending /-i/ and always before the feminine /-e/.