This paper presents an experiment that examined two related questions. First, it examined the effects of animacy on the production of different syntactic structures and word orders by Catalan-speaking children. Secondly, it explored the relationship between age and the production of different syntactic structures by these children. The results of a picture description experiment run with eighty Catalan-speaking children aged 4; 11 to 11; 11 show that participants tended to produce more object- dislocated descriptions when the patient was animate than when the patient was inanimate. The results also show that while the dislocation of object clauses is a construction already consolidated at 5; 0, the passive structure is a construction still not fully acquired at 11; 0. A comparison between the results obtained in the present experiment with existing results from similar experiments with English-speaking children shows that there is a cross-language difference in the age at which children start producing passive clauses. We argue that frequency of exposure to a particular syntactic structure is an important factor that contributes to the acquisition of that syntactic structure. We also suggest that the effects of animacy on the production of object-dislocated descriptions can be explained by means of conceptual and lexical accessibility.