Although English verbs can be either regular ("walk"-"walked") or irregular ("sing"-"sang"), "denominal verbs" that are derived from nouns, such as the use of the verb "ring" derived from the noun "a ring", take the regular form even if they are homophonous with an existing irregular verb: "The soldiers ringed the city" rather than "The soldiers rang the city". Is this regularization due to a semantic difference from the usual verb, or is it due to the application of the default rule, namely VERB+ "-ed" suffix? In Experiment 1, participants rated the semantic similarity of the extended senses of polysemous verbs and denominal verbs to their central senses. Experiment 2 examined the acceptability of the regular and irregular past tenses of the different verbs. The results showed that all the denominal verbs were rated as more acceptable for the regular inflection than the same verbs used polysemously, even though the two were semantically equally similar to the central meaning. Thus, the derivation of the verb (nominal or verbal) determined the past-tense preference more than semantic variables, consistent with dual-route models of verb inflection.