Phonological hierarchy

In phonology, the phonological hierarchy describes a series of increasingly smaller regions of an utterance. From larger to smaller units, it is as follows:


 * 1) Utterance
 * 2) Intonational phrase (I-phrase), or prosodic declination unit (DU)
 * 3) Phonological phrase (P-phrase), or prosodic intonation unit (IU)
 * 4) Prosodic list unit (LU)
 * 5) Clitic group
 * 6) P-word (ω) (prosodic or phonological word)
 * 7) Foot (F) e.g. "strong-weak" syllable groups, such as English ladder, button, eat it
 * 8) Syllable (σ) e.g. cat (1), ladder (2)
 * 9) Mora (μ) ("half-syllable")
 * 10) Segment (phoneme) e.g. [k], [æ] and [t] in cat
 * 11) Feature

The hierarchy from the mora upwards is also called the prosodic hierarchy.

Phonologists disagree on the arrangement and inclusion of units in the hierarchy. For example, the clitic group is not universally recognised, and the P-phrase and IU come from different traditions and have different definitions.