Syllable structure organizes segments into hierarchical constituents: the nucleus (usually a vowel) is the obligatory core; optional onsets precede it, optional codas follow. Phonotactic constraints operate at the level of syllable structure—codas may be restricted, onset clusters may require specific proportions of sonority. Syllable structure is not merely a phonetic convenience but a genuine phonological unit constraining sound patterns and phonological processes.
Identify syllable structure in various languages and explain phonotactic patterns as syllable-structure constraints. Examine cross-linguistic variation in what onsets and codas are permitted.
From your study of phonological systems and suprasegmental phonology, you already know that sounds are organized above the level of individual segments. Syllable structure is the first and most fundamental level of prosodic organization — the grouping of segments into the basic rhythmic units that all languages use, even languages whose speakers insist they cannot identify syllable boundaries (they can).
The internal structure of a syllable is hierarchical. Every syllable has a nucleus — the most sonorous element, typically a vowel — that forms its core. The nucleus, optionally preceded by an onset (one or more consonants before the vowel) and optionally followed by a coda (consonants after the vowel), makes up the syllable. The nucleus and coda together form the rhyme — the unit that matters for rhyming poetry and for tone-bearing in tonal languages. This internal structure reflects the sonority hierarchy, the cross-linguistic principle that sonority (roughly, loudness and openness) rises through the onset and falls through the coda. Vowels are maximally sonorous; obstruents minimally so. In a word like "strength," the onset rises from stop through approximant to vowel, and the coda falls from nasal through fricative to stop — a sonority arc that characterizes well-formed syllables cross-linguistically.
Languages vary enormously in what they permit in onset and coda positions. Some languages (like Hawaiian) permit only open syllables — CV — with no codas at all. Others (like Russian or German) permit complex onsets with three consonants and complex codas. These differences are not random: they follow from language-specific phonotactic constraints, which in OT terms are markedness constraints ranked differently across languages. Understanding syllable structure is therefore a prerequisite for understanding constraint-based phonology — the constraints on onsets, nuclei, and codas are the primary targets of markedness constraints and the primary site of cross-linguistic variation.
Syllable structure also governs phonological processes that operate above the level of individual segments. Resyllabification — the reassignment of segments to new syllable positions at morpheme boundaries — is systematic and predictable. Syllabification principles (like the Maximal Onset Principle: assign as many consonants as possible to the onset while respecting phonotactics) determine which consonant clusters attach to the preceding versus following syllable. Processes like vowel lengthening, tone assignment, and stress all reference syllable weight — whether a syllable is heavy (long vowel or coda consonant) or light (short vowel, no coda). The syllable is the prosodic atom around which higher-level phonological organization — stress systems, metrical feet, tone domains — is built.