Syllable - Structure

Structure

In most theories of phonology, the general structure of a syllable (σ) consists of three segments:

Onset (ω)

consonant, obligatory in some languages, optional or even restricted in others

Nucleus (ν)

sonorant, obligatory in most languages

Coda (κ)

consonant, optional in some languages, highly restricted or prohibited in others

The syllable is usually considered right-branching, i.e. nucleus and coda are grouped together as a "rime" and are only distinguished at the second level. However, in some traditional descriptions of certain languages, the syllable is considered left-branching, i.e. onset and nucleus group below a higher-level unit, called a "body" or "core":

Rime (ρ)

right branch, contrasts with onset, splits into nucleus and coda

Body or core

left branch, contrasts with coda, splits into onset and nucleus

In some theories the onset is strictly consonantal, thus necessitating another segment before the nucleus:

Initial (ι)

often termed onset, but leaving out semi-vowels

Medial (μ)

glide between initial, if any, and nucleus or rime

Final (φ)

contrasts with initial, extended rime

Although every syllable has supra-segmental features, these are usually ignored if not semantically relevant, e.g. in tonal languages.

Tone (τ)

may be carried by the syllable as a whole or by the rime

In some theories of phonology, these syllable structures are displayed as tree diagrams (similar to the trees found in some types of syntax). Not all phonologists agree that syllables have internal structure; in fact, some phonologists doubt the existence of the syllable as a theoretical entity.

The nucleus is usually the vowel in the middle of a syllable. The onset is the sound or sounds occurring before the nucleus, and the coda (literally 'tail') is the sound or sounds that follow the nucleus. They are sometimes collectively known as the shell. The term rime covers the nucleus plus coda. In the one-syllable English word cat, the nucleus is a (the sound that can be shouted or sung on its own), the onset c, the coda t, and the rime at. This syllable can be abstracted as a consonant-vowel-consonant syllable, abbreviated CVC. Languages vary greatly in the restrictions on the sounds making up the onset, nucleus and coda of a syllable, according to what is termed a language's phonotactics.