'Examples'| Word | Nucleus |
|---|
| c'a't | |
| b'e'd | |
| 'o'de | |
| b'ee't | |
| b'i'te | |
| r'ai'n | |
b'i'tt'e'n or | or |
In
phonetics and
phonology, the 'nucleus' (sometimes called 'peak') is the central part of the
syllable, most commonly a
vowel. In addition to a nucleus, a syllable may begin with an
onset and end with a
coda, but the only part of a syllable that is mandatory is the nucleus. The nucleus and coda form the
rime of the syllable.
Diphthongs and
triphthongs can also serve as the nucleus. Syllables with
short vowels as nuclei are sometimes referred to as "light syllables" while syllables with
long vowels, diphthongs, or triphthongs as nuclei are referred to as "heavy syllables"; see ''
Syllable weight'' for more discussion.
Sonorant consonants such as
liquids (such as and ) and
nasals (such as and ) can serve as the nucleus if there is no
vowel. The nucleus of the last syllable in the final example at right is an example of a sonorant nucleus. Some languages allow other sounds, such as
stops, to become nuclei.