This paper deals with the interface phonology-syntax by discussing the role of empty categories in the application of rhythmic rules (see among others Lightfoot 1976, Postal & Pullum 1978, Andrews 1978, Jaeggli 1980, Freidin & Lasnik 1981). I examine configurations of potential stress clash of the sort [V ec Adv], where V is a verb with stress on its final syllable, ec is an empty category, and Adv is an adverb with stress on its first syllable. I argue that the stress clash in such environment can be resolved by retraction of the first stress if ec is a trace of movement, but not if it is a null pronoun (pro).
trace; null pronoun; stress clash; rhythmic rules