This paper argues that intonational phrasing in English is subject to
two constraints formulated purely in terms of surface syntax. The firs
t applies to all headed structures, and the second to all structures o
f coordination. It is claimed that these constraints account for the f
acts more adequately than Selkirk's Sense Unit Condition. Several prob
lematic types of constructions are discussed in this context, includin
g structures with parentheticals. In addition to the syntax, accent pl
acement is also shown to be relevant to intonational phrasing. Finally
, proposals are made for the incorporation of the syntactic constraint
s in an HPSG grammar of English.