We investigate the production of relative clauses in Italian children aged 3 years, 4 months to 8 years, 10 months and in adults, focusing on object relatives (ORs). For both adults and older children, we test the production of passive ORs (PORs) as an alternative to the production of active ORs. We also test the comprehension of active ORs and PORs in older children, showing that the comprehension of the latter is significantly more accurate than the former. The persistent difficulty that children experience with ORs is interpreted as due to intervention, following Friedmann, Belletti, and Rizzi (2009). We assume Collins’ (2005) approach to passive and account for the increasing use and more accurate comprehension of PORs as a consequence of lack of intervention, as in Belletti (2009a).