Syllables and metrical feet

English syllable structure is assigned by the following (radically simplified) set of phrase structure rules (see also Coleman 1992):

Syl --> (On / Ri).

   On --> (closure:[-nas] / cons:[GLIDE]).
   On --> closure.  
   On --> cons:[GLIDE].
   On:[+empty].

   closure:[nas=A] -->
     (cons:[-voi, +str, ALVEOLAR, FRICATIVE] 
     / cons:[-cnt, -str, voi=A, nas=A]).
   closure:[nas=A] --> cons:[-cnt, -str, nas=A].
   closure --> cons:[FRICATIVE].

   Ri:[heavy=A] --> (Nu:[branching=A] \ Co:[branching=A]).

   Nu --> ...

   Co --> (cons:[+coda, GLIDE] \ cons:[-son]).
   Co --> (cons:[NASAL, cns=A] \ cons:[-son, cns=A]).
   Co --> cons:[+coda].
   Co:[+empty].

Rules for the nucleus are presented elsewhere, as well as some of the necessary feature definitions (see: Vowels and consonants).

The following template is used to assure that branching nuclei and codae are marked as [+branching], whereas non-branching nodes are left unspecified for this feature:

[+branching] --> [], [].

Also, templates are used to assign the features heavy and stress the status of head-features:

[heavy=A, stress=B] --> ([] / [heavy=A, stress=B]).
   [heavy=A, stress=B] --> ([heavy=A, stress=B] \ []).
   [heavy=A, stress=B] --> [heavy=A, stress=B].

As a result, a syllable is marked as [+heavy] if the nucleus or the coda branches. Otherwise, a syllable is left unspecified for this feature.

Syllables are grouped into metrical feet by rules such as the following, which assure that heavy syllables are analyzed as the head of a foot.

Foot --> 
     ((Syl:[+stress] \ Syl:[-heavy, -stress]) \ Syl:[-heavy, -stress]).
   Foot --> 
     (Syl:[+stress] \ Syl:[-heavy, -stress]).
   Foot --> Syl:[+stress].

Note, however, that the above rules do not represent a fully developed analysis of English word stress.