Aspectual interpretations are compositional and depend on the language-specific properties of the components (Verkuyl 1972, Krifka 1998, a.o.). Although a telic predicate built with an incremental theme verb taking a quantized direct object (e.g., I ate three cookies.) entails event culmination in English, its Mandarin counterpart seems to allow non-culminating interpretations (Tai 1984, Koenig & Chief 2008, a.o.). To account for the different interpretations associated with incremental theme predicates, some researchers postulate a fundamental difference between the semantics of verbs in English and Mandarin: while English verbs entail culmination, their Mandarin counterparts only imply culmination (Tai 1984, Koenig & Chief 2008). As for Mandarin children, Li (2019) argues that they represent the verbs as entailing completion, since they reject telic descriptions of incomplete situations more often than adults in experimental situations. However, the cross-linguistic claims are difficult to compare due to the use of different materials and experimental setups across studies. Using experimental designs that control for verb-type and determiner-type of the direct object, the present study presents a finer-grained examination of the aspectual interpretations of incremental theme predicates in English adults and Mandarin adults and children (age 4-6). We provide evidence for no radical differences between English and Mandarin incremental theme verbs. Moreover, we observe a determiner-type difference in both Mandarin and English adults, which suggests some pragmatic accommodations associated to the demonstrative. Mandarin children's understanding of verbs aligns with adults', but they take longer to master the pragmatic use of demonstratives.