Metrical Phonology - Metrical Grids

Metrical Grids

In a Metrical grid, all the words in the phrase are arranged along the bottom and the rows of the grid indicate different levels of prominence, as in (3).

(3) Example metrical grid

The higher the column of Xs above a syllable, the more prominent the syllable is. The metrical grid and the metrical tree for a particular utterance are related in such a way that the Designated Terminal Element of an S node must be more prominent than the Designated Terminal Element of its sister W node. So in (3), the metrical grid for the utterance in (1), '-ci-' must be more prominent than 'doc-' because '-ci-' is the Designated Terminal Element of the highest S node and 'doc-' is the Designated Terminal Element of its sister W node.

The structure of the metrical grid explains a number of otherwise surprising features of prominence patterns in language. For example, the main stress in English phrases may be placed several syllables away from the end of the phrase, even though the rule assigning this stress looks for a lexically stressed syllable near this boundary. Using a metrical grid, this rule can simply apply to the rightmost element in the highest row of the grid. Therefore, what seemed to be a non-local application of the phrasal stress rule is reinterpreted as the local application of the rule to the highest row of the metrical grid.

Metrical grids were originally developed to handle a phenomenon that appears in some languages, including English, German, and Masoretic Hebrew, in which stress shifts to avoid a 'stress clash'. A stress clash can occur when two stressed syllables are too close to each other. For example, the word 'nineteen' spoken in isolation has stress on the second syllable. But when it is placed before 'girls' the stress on 'nineteen' can shift to the first syllable. Two syllables exhibit stress clash if there are two successive rows in the grid in which their columns are adjacent (i.e. there is no X between them). For example, in grid (4) the columns for 'teen' and 'girls' are adjacent in both the first and second rows, indicating a stress clash.

(4) Pre-stress-shift metrical grid

Stress clashes can be resolved by the Rhythm Rule, which reverses the S-W relation for some pair of sister nodes, as long as such a reversal does not put a Designated Terminal Element of an Intonational Phrase under any W node, and doesn't put a syllable directly under an S node. In (4) the W and S nodes over 'nine-' and '-teen' can be reversed, leading to the non-clashing grid in (5).

(5) Post-stress-shift metrical grid

This process is optional, and seems to be applied more often in some circumstances than others.