|Voiceless alveolo-palatal fricative|
The voiceless alveolo-palatal sibilant fricative is a type of consonantal sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is ⟨ɕ⟩ ("c", plus the curl also found in its voiced counterpart ⟨ʑ⟩). It is the sibilant equivalent of the voiceless palatal fricative, and as such it can be transcribed in IPA with ⟨ç˖⟩.
In British Received Pronunciation, /j/ after syllable-initial /p, t, k/ (as in Tuesday) is realized as a devoiced palatal fricative. The amount of devoicing is variable, but the fully voiceless variant tends to be alveolo-palatal [ɕ] in the /tj/ sequence: [ˈt̺ʲɕuːzdeɪ]. It is a fricative, rather than a fricative element of an affricate because the preceding plosive remains alveolar, rather than becoming alveolo-palatal, as in Dutch.
The corresponding affricate can be written with ⟨t̠ʲ͡ɕ⟩ or ⟨c̟͡ɕ⟩ in narrow IPA, though ⟨tɕ⟩ is normally used in both cases. In the case of English, the sequence can be specified as ⟨t̺ɕ⟩ as /t/ is normally apical (although somewhat palatalized in that sequence), whereas alveolo-palatal consonants are laminal by definition.
An increasing number of British speakers merge this sequence with the voiceless palato-alveolar affricate /tʃ/: [ˈtʃuːzdeɪ] (see yod-coalescence), mirroring Cockney, Australian English and New Zealand English. On the other hand, there is an opposite tendency in Canadian accents that have preserved /tj/, where the sequence tends to merge with the plain /t/ instead: [ˈt̺ʰuːzdeɪ] (see yod-dropping), mirroring General American which does not allow /j/ to follow alveolar consonants in stressed syllables.