The phonological hierarchy describes a series of increasingly smaller regions of a phonological utterance, each nested within the next highest region.
Listed in order from highest to lowest are the categories of the hierarchy that are most commonly used in theoretical phonology.
There is some disagreement on the arrangement and inclusion of units, especially those that reside higher in the hierarchy.
For example, the clitic group is not considered to be a separate level in Selkirk's version of the hierarchy,[1] while the minor phrase or accentual phrase are not considered to be separate from the phonological phrase in Hayes'[2] and Nespor & Vogel's hierarchies.
The phonological hierarchy as it is defined in the discourse analytical tradition is listed below.