Palatalization involves change in the place or manner of articulation of consonants, or the fronting or raising of vowels.
[citation needed] Palatalization, as a sound change, is usually triggered only by mid and close (high) front vowels and the semivowel [j].
A similar change is reconstructed in the history of Old French in which Bartsch's law turned open vowels into [e] or [ɛ] after a palatalized velar consonant.
Old historical splits have frequently drifted since the time they occurred and may be independent of current phonetic palatalization.
In Japanese, allophonic palatalization affected the dental plosives /t/ and /d/, turning them into alveolo-palatal affricates [tɕ] and [dʑ] before [i], romanized as ⟨ch⟩ and ⟨j⟩ respectively.
Japanese has, however, recently regained phonetic [ti] and [di] from loanwords, and the originally-allophonic palatalization has thus become lexical.
That would also be true about most dialects of Brazilian Portuguese but for the strong phonotactical resistance of its native speakers that turn dental plosives into post-alveolar affricates even in loanwords: McDonald's [mɛkiˈdõnɐwdʒ(is)].
For example, Votic has undergone such a change historically, *keeli → tšeeli 'language', but there is currently an additional distinction between palatalized laminal and non-palatalized apical consonants.
An extreme example occurs in Spanish, whose palatalized ('soft') g has ended up as [x] from a long process where Latin /ɡ/ became palatalized to [ɡʲ] (Late Latin) and then affricated to [dʒ] (Proto-Romance), deaffricated to [ʒ] (Old Spanish), devoiced to [ʃ] (16th century), and finally retracted to a velar, giving [x] (c. 1650).
This is the origin of some alternations in cognate words, such as speak and speech /ˈspiːk, ˈspiːtʃ/, cold and chill /ˈkoʊld, ˈtʃɪl/, burrow and bury /ˈbʌroʊ, ˈbɛri/, dawn and day /ˈdɔːn, ˈdeɪ/.
Some English words with palatalization have unpalatalized doublets from the Northumbrian dialect and from Old Norse, such as shirt and skirt /ˈʃərt, ˈskərt/, church and kirk /ˈtʃɜrtʃ, ˈkɜrk/, ditch and dike /ˈdɪtʃ, ˈdaɪk/.
German only underwent palatalization of /sk/: cheese /tʃiːz/ and Käse /kɛːzə/; lie /ˈlaɪ/ and liegen /ˈliːɡən/; lay /ˈleɪ/ and legen /ˈleːɡən/; fish and Fisch /fɪʃ/.
It is not well known when this change occurred or if it is connected to the pronunciation of Qāf ⟨ق⟩ as a [ɡ], but in most of the Arabian peninsula which is the homeland of the Arabic language, the ⟨ج⟩ represents a [d͡ʒ] and ⟨ق⟩ represents a [ɡ], except in western and southern Yemen and parts of Oman where ⟨ج⟩ represents a [ɡ] and ⟨ق⟩ represents a [q], which shows a strong correlation between the palatalization of ⟨ج⟩ to [d͡ʒ] and the pronunciation of the ⟨ق⟩ as a [ɡ] as shown in the table below: Some modern Arabic varieties developed palatalization of ⟨ك⟩ (turning [k] into [tʃ], [ts], [ʃ], or [s]), ⟨ق⟩ (turning [ɡ~q] into [dʒ] or [dz]) and ⟨ج⟩ (turning [d͡ʒ] into [j]), usually when adjacent to front vowel, though these palatalizations also occur in other environments as well.
In Gallo-Romance, Vulgar Latin *[ka] became *[tʃa] very early (and then in French become [ʃa]), with the subsequent deaffrication and some further developments of the vowel.
Mouillé (French pronunciation: [muje], "moistened") is a term for palatal consonants in the Romance languages.
In certain Indo-European language groups, the reconstructed "palato-velars" of Proto-Indo-European (*ḱ, *ǵ, *ǵʰ) were palatalized into sibilants.
In the second palatalization, the velars changed to *c, *dz or *z, and *s or *š (depending on dialect) before new *ē *ī (either from monophthongization of previous diphthongs or from borrowings).
Postal romanization does not show palatalized consonants, reflecting the dialect of the imperial court during the Qing dynasty.