We examine the prosodic characteristics of read speech produced alone or in synchrony with a co-speaker in English. Previous work has demonstrated a marked difference between these two speaking conditions in Mandarin, but not English. We employ word lists that are either simple sequences of trochees, or complex lists with regular stress alterantion but irregular word boundaries. Inter-onset intervals are examined and no major differences between solo and synchronous interval sequences are found. Viewed from the perspective of two generative models, however, there is weak evidence for some small difference in the dependence of interval duration on serial position.