A characteristic of Mashreqi varieties of Arabic is to assibilate the interdental consonants of Modern Standard Arabic in certain contexts. Thus, ṯāʾ, pronounced in MSA, becomes ; ḏāl, pronounced in MSA, becomes ; and ẓāʾ, pronounced in MSA, becomes . Diachronically, the phoneme represented by the letter ǧīm has in, some dialects, experienced assibilation as well. The pronunciation in Classical Arabic is reconstructed to have been or ; it is cognate to in most other Semitic languages, and it is understood to be derived from that sound inProto-Semitic. It has experienced extensive change in pronunciation over the centuries, and is pronounced at least six different ways across the assorted varieties of Arabic. A common one is, the end result of a process of palatalization starting with Proto-West Semitic, then or, then and finally . The last pronunciation is considered acceptable for use in MSA, along with and.
had changed to. The alternation can be seen in dialectal and inflected word forms: Finnish kieltää "to deny" → kielti ~ kielsi "s/he denied"; vesi "water" vs. vete-nä "as water". An intermediate stage is preserved in South Estonian in certain cases: tsiga "pig", vs. Finnish sika, Standard Estonian siga.
Germanic languages
In the High German consonant shift, voiceless stops spirantized to at the end of a syllable. The shift of to is assibilation. Assibilation occurs without palatalization for some speakers of African American Vernacular English in which is alveolarized to when it occurs at the end of a syllable and within a word before another consonant, leading to such pronunciations as the following:
Greek
In Proto-Greek, the earlier combinations *ty, *thy and *dy assibilated to become alveolar affricates, *ts and *dz, in what's known as the first palatalization. Later, a second round of palatalization occurred, initially producing geminate palatal *ťť and *ďď from various consonants followed by *y. The former was depalatalised to plain geminate tt in some dialects, and assibilated to ss in others. The latter evolved into an affricate dz in all Greek dialects. Some examples:
The word "assibilation" itself contains an example of the phenomenon, as it is pronounced. The Classical Latin -tio was pronounced . However, in Vulgar Latin, it assibilated to, which can still be seen in Italian: attenzione. In French, lenition then gave ., which was further palatalized in the English derived words to . Most dialects of Quebec French apply a more recent assibilation to all dental plosive consonants immediately before high front vowels and associated semivowels, so that the sequences become pronounced respectively. Assibilation can occur in some varieties of Spanish such as in Ecuador and Mexico. It is closely related to the phonetic termsibilation.
Palatalization effects were widespread in the history of Proto-Slavic. In the first palatalization, various consonants were converted into postalveolar fricatives and affricates, while in the second and third palatalizations, the results were alveolar. Some Slavic languages underwent yet another round of palatalisation. In Polish, in particular, dental consonants became alveolo-palatal fricatives and affricates when followed by a front vowel.
