rhythm

n. The rhythm of an utterance is the way its constituent parts are timed with respect to each other. Along with intonation, rhythm is a prosodic property of utterances. The most basic rhythmic units are moras (vowels or consonants in the rhyme of a syllable) and syllables (sequences of consonants and vowels obligatorily containing a nucleus, usually a vowel, flanked by an optional onset and/or coda, usually consonants or consonant clusters). Syllables combine to create feet, in which one syllable receives more prosodic prominence than the rest. Bisyllabic feet are iambic (e.g., portray) or trochaic (e.g., portrait), depending on which syllable is more prominent. Languages can be classified into those whose lexical stock is predominantly iambic (e.g., French) or trochaic (e.g., English). Languages have been classified as mora-timed (e.g., Japanese), syllable-timed (e.g., Spanish), or stress-timed (e.g., English), though these categories are not yet well understood or empirically supported. Higher-order rhythmic units include pitch accents, signaled by increased pitch movement and duration, and intonational phrases, marked by intonational contours as well as by phrase-final lengthening and optional pausing. Certain structural ambiguities, like We gave her dog biscuits, can be disambiguated rhythmically, by pitch accenting different words and grouping them into different intonational phrases. – EMF