Syllable Structure

The Sonority Sequencing Principle (SSP), developed by Sievers (1881), Hooper (1976), Selkirk (1984), and Clements (1990), states that sonority rises from the syllable margin to the nucleus and falls again. Sonority hierarchy: vowels (highest) > glides [w, j] > liquids [l, r] > nasals [m, n] > fricatives [s, f] > stops [p, t, k] (lowest). English "plant" has rising onset [pl], peak [æ], falling coda [nt] — well-formed by SSP. Reverse onsets (e.g., [lp]) violate SSP and are rare. Exceptions exist — "stop" begins [st], a sibilant before a stop, treated as extrasyllabic or as a CC complex onset by analysts.

The rime (or rhyme) is the nucleus plus coda — what remains when the onset is removed. Words rhyme when their rimes match. English poetry exploits rime — "cat" and "hat" rhyme on /æt/. Phonologically, the rime is a constituent — many phenomena reference it as a unit. Stress weight depends on rime structure (heavy rimes attract stress in Latin). Speech errors preserve onset-rime structure (slips of the tongue swap rimes more than nuclei alone). Children's nursery rhymes and phonological awareness tasks rely on rime intuition.

Syllable boundaries are not always clear in fast speech. The Maximal Onset Principle states that consonants between vowels group into the following syllable's onset where phonotactically licensed — "nitrate" syllabifies as ni-trate, not nit-rate. Languages enforce different constraints. Resyllabification across word boundaries occurs in French liaison ("les amis" — [le.za.mi]), English glottal-stop allophony, and Spanish cliticization. Underlying syllabification (lexical) and surface syllabification (post-lexical) may differ. Syllabification is computed online and can shift with speech rate and register.

Salishan languages (Bella Coola, Nuxalk) allow long stretches of consonants without intervening vowels — sequences like [xɬpʼχʷɬtʰɬpʰɬːskʷʰt͡sʼ] (a real Bella Coola word meaning roughly "he had had a bunchberry plant"). Whether such sequences contain syllabic obstruents (consonants serving as syllable nuclei) is debated. Berber languages similarly allow consonant-only sequences. Hawaiian and Japanese are at the opposite extreme — strict CV(N), with no consonant clusters and severely restricted codas. The cross-linguistic range of syllable complexity is one of the largest typological dimensions in phonology.

Infants babble starting around six months, producing CV syllables (mama, baba, dada). First words appear around twelve months, mostly CV or CVCV (reduplicated). Closed syllables (CVC) emerge by eighteen months in English. Consonant clusters are mastered later — English children often simplify "stop" to [tap] or "block" to [bak]. Carol Stoel-Gammon's longitudinal studies catalogued the acquisition order. Children's productions are constrained by motor maturation and phonotactic learning. Cross-linguistic acquisition (Marilyn Vihman's Phonological Development, 1996) shows the CV-first generalization holds across languages.

Moraic theory, developed by Bruce Hayes (1989) and Junko Itô (1989), replaces the syllable-internal CVC structure with weight units (moras). A short vowel is one mora; a long vowel or diphthong is two; a coda consonant may contribute one mora (in weight-sensitive languages). The mora replaces the syllable as the unit referenced for stress, length, and compensatory phenomena. Moraic theory captures Japanese rhythm (the language counts moras, not syllables — Tokyo is to-u-kyo-u, four moras), Latin stress, and tone-mora alignment in Bantu languages.

Many morphological processes target syllables. Reduplication often copies a syllable or partial syllable (Tagalog basa "read" → bababasa "will read by anyone"). Hypocoristic formation in English ("Roberto" → "Bobby") shapes outputs to a binary trochee — two syllables, strong-weak. Truncation in Spanish nicknames similarly targets syllabic templates. McCarthy and Prince's prosodic morphology (1986) showed that morphological processes are constrained by phonological prosodic categories, especially the syllable, foot, and prosodic word. The morphology-phonology interface is heavily syllable-mediated.