This article challenges the commonly-held assumption that words, feet and s
yllables fit into a single phonological hierarchy, and in particular that f
eet are always sub-units of words. A number of facts of English rhythm are
cited which cannot be accounted for unless words and feet are taken to be u
nits of different hierarchies: many of the differences of rhythm between ph
rases of otherwise similar phonological structure which are noted by Abercr
ombie (1964) are accounted for most naturally by differences in placement b
etween, on the one hand, word- and stress-group-boundaries, and, on the oth
er, foot-boundaries.