The present study investigates the role of three structural factors ("word order," "case-marking," and "verbal morphology") in the comprehension of the Korean suffixal passive by Korean-speaking children. To measure the relative impact of each factor on the comprehension of the passive, we devise a novel method where these factors are obscured systematically by employing acoustic masking -- chewing and coughing. Results from three picture selection tasks show that (1) the Agent-First preference is not ubiquitously employed by young children, but is dependent on other grammatical cues; (2) despite mediocre accuracy rates on passive sentences, we nonetheless find evidence that children have some knowledge about the passive construction; and (3) scrambling of passive sentences does not aid in comprehension. These findings suggest that, in order to understand the acquisition of the passive, all these structural factors need to be considered.