The goal of this paper is to examine the second language acquisition (SLA) of telicity marking in English by native speakers of Hungarian. The framework of the investigation is that of principles-and-parameters, complemented with the latest syntactic analysis of telicity in Hungarian (Kardos & Farkas 2018). There is substantial literature on the SLA of different aspectual properties, but Hungarian has not been studied from this perspective. This research is important as it presents novel findings regarding the SLA of telicity in English by Hungarian learners. Hungarian is best described with telicity represented in the syntax, and I contrast the structural decomposition with the syntax of VP-level aspect in English, and it is from this perspective that the differences between the two languages gain experimental significance. Two views on L1 language transfer that are counterpointed are the full-transfer/full access hypothesis (Schwartz and Sprouse 1994, 1996, 1998) and the no-transfer/full-access hypothesis (Epstein et al. 1996, 1998). In a cross-sectional study, L1 speakers of Hungarian are tested on their intuitions about telicity marking in English, and in line with previous research, it is the full-transfer/full-access hypothesis that receives empirical support.