Many generativist accounts argue for very early knowledge of inflection on the basis of very low rates of person/number marking errors in young children's speech. However, studies of Spanish and Brazilian Portuguese have revealed that these low overall error rates actually hide important differences across the verb paradigm. The present study investigated children's production of person/number marked verbs by eliciting present tense verb forms from 82 native Finnish-speaking children aged 2;2–4;8 years. Four main findings were observed: Rates of person/number marking (...) errors were higher in low-frequency person/number contexts, even excluding children who showed no evidence of having learned the relevant morpheme, most errors involved the use of higher frequency forms in lower frequency person/number contexts, error rates were predicted not only by the frequency of person/number contexts but also by the frequency of individual “ready-inflected” lexical target forms, and for low-frequency verbs, lower error rates were observed for verbs with high phonological neighborhood density. It is concluded that any successful account of the development of verb inflection will need to incorporate both rote-storage and retrieval of individual inflected forms and phonological analogy across them. (shrink)