In phonetics, alveolo-palatal (alveolopalatal, alveo-palatal or alveopalatal) consonants, sometimes synonymous with pre-palatal consonants, are intermediate in articulation between the coronal and dorsal consonants, or which have simultaneous alveolar and palatal articulation. In the official IPA chart, alveolo-palatals would appear between the retroflex and palatal consonants but for "lack of space".^[1] Ladefoged and Maddieson characterize the alveolo-palatals as palatalized postalveolars (palato-alveolars), articulated with the blade of the tongue behind the alveolar ridge and the body of the tongue raised toward the palate,^[2] whereas Esling describes them as advanced palatals (pre-palatals), the furthest front of the dorsal consonants, articulated with the body of the tongue approaching the alveolar ridge.^[1] These descriptions are essentially equivalent, since the contact includes both the blade and body (but not the tip) of the tongue (see schematic at right). They are front enough that the fricatives and affricates are sibilants, the only sibilants among the dorsal consonants.

According to Daniel Recasens, alveolo-palatal consonants are realized through the formation of a simultaneous closure or constriction at the alveolar and palatal zones with a primary articulator which encompasses the blade and the tongue dorsum. Their place of articulation may include the postalveolar zone and the prepalate, but also a larger contact area extending towards the front alveolar zone and the back palate surface. The tongue tip is bent downwards and the tongue dorsum is raised and fronted during the production of these consonants.^[3]

Sibilants

The alveolo-palatal sibilants are often used in varieties of Chinese such as Mandarin, Hakka, and Wu, as well as other East Asian languages such as Japanese and Korean, Tibeto-Burman such as Tibetan and Burmese as well as Tai languages such as Thai, Lao, Shan and Zhuang. Alveolo-palatal sibilants are also a feature of many Slavic languages, such as Polish, Russian, and Serbo-Croatian, and of Northwest Caucasian languages, such as Abkhaz and Ubykh. The alveolo-palatal consonants included in the International Phonetic Alphabet are:

The letters ⟨ɕ⟩ and ⟨ʑ⟩ are essentially equivalent to ⟨ ʃʲ⟩ and ⟨ʒʲ⟩. They are the sibilant homologues of the pre-palatal fricatives [ç˖] and [ʝ˖].

Stops, nasals, and liquids

Symbols for alveolo-palatal stops U+0236 ȶ LATIN SMALL LETTER T WITH CURLU+0221 ȡ LATIN SMALL LETTER D WITH CURL(ȶ, ȡ), nasals U+0235 ȵ LATIN SMALL LETTER N WITH CURL(ȵ) and liquids U+0234 ȴ LATIN SMALL LETTER L WITH CURL(ȴ) are sometimes used in sinological circles (a circumflex accent is also sometimes seen), but they are not recognized by the IPA.

In standard IPA, they can be transcribed ⟨t̠ʲ d̠ʲ n̠ʲ l̠ʲ⟩ or ⟨c̟ ɟ̟ ɲ̟ ʎ̟⟩. An alternative transcription for the voiced alveolo-palatal stop and nasal is ⟨ɟ˖ ɲ˖⟩, but it is used only when ⟨ɟ̟ ɲ̟⟩ cannot be displayed properly.

For example, the Polish nasal represented with the letter ń is a palatalized laminal alveolar nasal and thus often described as alveolo-palatal rather than palatal. The "palatal" consonants of Indigenous Australian languages are also often closer to alveolo-palatal in their articulation.

Contrasting with palatovelar consonants

In Migueleño Chiquitano, phoneme /ȶ/ contrasts with phoneme /c̠/;^[4] in the syllabic coda (or intervowel) position in conservative Irish, laminal alveolo-palatal phoneme /ṉʲ/ (termed fortis slender coronal nasal, orthographic example inn) contrasts with both dorsal palatal phoneme /ɲ/^[5] (termed slender dorsal nasal, orthographic example ing or -nc-) and apical palatalized alveolar phoneme /nʲ/ (termed lenis slender coronal nasal, orthographic example in);^[6] while general Irish other than Munster Irish contrasts alveolo-palatal nasal only with palatal nasal. In both cases, the palatal consonants work as the palatalization of velar consonants while alveolo-palatal consonants work as the palatalization of alveolar consonants.

In some spoken Chinese varieties, such as the Luchuan Hakka [zh] in Hengshan [zh], contrast the alveolo-palatal nasal with the palato-velar nasal. For example, the following contrasting pairs can bs found in Luchuan Ngai.

Although a number of spoken Chinese varieties, such as standard Mandarin, also contrast EMC alveolo-palatal nasal with velar nasal of class III (palatalizing medial), most don't contrast them in a way that alveolo-palatal differs from palatal. For example, in Pianlian [Wikidata] Hakka, alveolo-palatal nasal marginally contrasts with velar nasal under close front medials, but there is little sign of palatal contrasts.

Thus most frequently, the Sinologist use of ȵ instead of ɲ is not to indicate a contrast, but to emphasize its primary allophone not to be the Turkish [ɲ], or to indicate its coronal origin or that it has evolved with other dorsal consonants which have become alveolopalatals, where ɲ is reserved for postpalatals evolved from dorsal consonants. However, since ȵ has also been unfortunately used by some for Meixian Hakka, the distinction of usage has become vague. ȶ, on the other hand, has retained its accurate usage representing phonemes in certain spoken Chinese in Hengyang and has never been applied on Hakka or on certain Mandarin in or near Shandong.