Many studies show a developmental advantage for transitive sentences with familiar verbs over those with novel verbs. It might be that once familiar verbs become entrenched in particular constructions, they would be more difficult to understand (than would novel verbs) in non-prototypical constructions. We provide support for this hypothesis investigating German children using a forced-choice pointing paradigm with reversed agent-patient roles. We tested active transitive verbs in study 1. The 2-year olds were better with familiar than novel verbs, while the (...) 2½-year olds pointed correctly for both. In study 2, we tested passives: 2½-year olds were significantly below chance for familiar verbs and at chance for novel verbs, supporting the hypothesis that the entrenchment of the familiar verbs in the active transitive voice was interfering with interpreting them in the passive voice construction. The 3½-year olds were also at chance for novel verbs but above chance with familiar verbs. We interpret this as reflecting a lessening of the verb-in-construction entrenchment as the child develops knowledge that particular verbs can occur in a range of constructions. The 4½-year olds were above chance for both familiar and novel verbs. We discuss our findings in terms of the relative entrenchment of lexical and syntactic information and to interference between them. (shrink)