Research in the active-passive verb relation has indicated that there is an interaction between syntactic form and verb semantics among children of preschool age. The present study examines the contribution of active-passive syntax and verb semantics to comprehension difficulty for preschoolers, 6-year-olds, 7-year-olds, and adults. An additional variable is the type of patient (animate or inanimate) in the sentences. Data were examined from the results of a previous passive comprehension study involving a simple picture-cued comprehension test given to 38 preschool children. The subjects had to point to one of two pictures for each of 24 sentences, 12 active and 12 passive. All the children responded correctly to the 12 reversible sentences. However, the results show a significant interaction between syntax and verb type. A verification test was run on 26 7-year-olds, 26 6-year-olds, and 26 college students. All results agreed: both syntax and verb type had a significant effect on reaction time, but there was no interaction between these variables. While the basic finding remains, that children understand action verb passives better than they understand passives with other verb types, more study is needed to determine whether this phenomenon reflects piecemeal acquisition of knowledge or a general difficulty in processing verbs that do not refer to clear actions. (AMH)