This paper argues for a syntactic approach to aspectuality, where sema
ntic information about subevent structure is incorporated into the phr
ase marker. Such an approach would be justified only if aspectual prop
erties present syntactic as well as semantic effects. It is the aim of
the paper to present evidence of such syntactic effects. Slavic preve
rbs have standardly been regarded as perfectivizing (or telicity-marki
ng) morphemes. It will be argued that preverbs are also causative morp
hemes. As such, they are situated in the upper part of a VP-layer stru
cture, a light verb widely accepted to be reserved for CAUSE. In Engli
sh, the aspectual interpretation of a terminative or durative event de
pends on the specified or unspecified cardinality of the object (Verku
yl 1993) and aspect is calculated in a functional projection AspP betw
een the two VP layers (Travis 1991). In Slavic, on the other hand it i
s the presence oi absence of a preverb in the upper verbal head that e
ncodes a terminative ol a durative interpretation. This contrast is ex
plained with the relatively higher structural position of Slavic preve
rbs with respect to the functional projection AspP in English. Similar
scope effects are demonstrated with articles in Russian, with interpr
etations of Polish and English imperfective sentences, and with manner
adverbs in Bulgarian.