Phonological Hierarchy

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

1. Utterance
2. Prosodic declination unit (DU) / intonational phrase (I-phrase)
3. Prosodic intonation unit (IU) / phonological phrase (P-phrase)
4. Prosodic list unit (LU)
5. Clitic group
6. Phonological word (P-word, ω)
7. Foot (F): "strong-weak" syllable sequences 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., and in cat
11. Feature

The hierarchy from the mora upwards is technically known as the prosodic hierarchy.

There is some disagreement among phonologists 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.