Syllable onset
In
phonetics and
phonology, a
syllable onset is the part of a
syllable that precedes the
syllable nucleus. In the study of
Chinese languages, onsets are better known as
initials or in Chinese,
shengmu (
PY: shēngmǔ,
TC: 聲母,
SC: 声母).
The segmental structure of a
syllable begins with an optional onset, followed by a compulsory
rime or final (
yunmu).
syllable: C
1(C
2)V
1(V
2)(C
3)(C
4) = onset: C
1(C
2) + rime: V
1(V
2)(C
3)(C
4):syllable: V
1(V
2)(C
3)(C
4) = onset: Ø (null) + rime: V
1(V
2)(C
3)(C
4):(C = consonant, V = vowel, optional components are in parentheses.)
Depending on the
phonotactics of a language, the onset can consist of a single
consonant or a
consonant cluster. If a syllable begins with a
vowel or another syllabic
sonorant, then the syllable is said to have no onset, or a
null onset. In Chinese language studies, the terms
null initial and
zero initial are used as well.
The onset or initial was first called
shēngniǔ (TC: 聲紐, SC: 声纽), or simply
shēng or
niǔ, in traditional phonological studies since the
Jìn Dynasty. For each group of characters pronounced with the same initial consonant, one was picked to name the initial. One character was also picked from the group without an initial consonant, which was the beginning of the concept of the null initial.
