In phonetics, alveolo-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". 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, 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. 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.
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:
|?||Voiceless alveolo-palatal sibilant||Mandarin||? (xi?o)||[?i?u]||small|
|?||Voiced alveolo-palatal sibilant||Polish||zio?o||[??w?]||herb|
|t||Voiceless alveolo-palatal affricate||Serbo-Croatian||ku?a / ??||[kuta]||house|
|d||Voiced alveolo-palatal affricate||Japanese||(jishin)||[di]||earthquake|
The letters ⟨?⟩ and ⟨?⟩ are essentially equivalent to ⟨ ⟩ and ⟨⟩. They are the sibilant homologues of the pre-palatal fricatives [ç?] and .
Symbols for alveolo-palatal stops (?, ?), nasals (?) and liquids (?) are sometimes used in sinological circles (a circumflex accent is also sometimes seen), but they are not recognized by the IPA. They may be simple palatal or palatalized consonants, classified as alveolo-palatals because they pattern with the alveolo-palatal sibilants of the language rather than because they are alveolo-palatal in articulation.
In standard IPA, they can be transcribed ⟨t d n l⟩ or ⟨c? ⟩. An alternative transcription for the voiced alveolo-palatal stop and nasal is ⟨ ⟩, but it is used only when ⟨ ⟩ cannot be displayed properly.
For example, the Polish nasal represented with the letter ? 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.
|?, t?||t, c?||Voiceless alveolo-palatal stop||Korean||tikkeul||[ti?kl]||dust|
|?, d?||d,||Voiced alveolo-palatal stop||Korean||bandi||[bndi]||firefly|
|?, n?||n,||Alveolo-palatal nasal||Nuosu||? nyi||[ni?]||sit|
|?, l?||l,||Alveolo-palatal lateral||Catalan||ull||['ul]||eye|