The null object/overt pronoun split in Brazilian Portuguese has been assimilated to differential object marking in some functionalist accounts (Schwenter and Silva 2002, Schwenter 2006). This paper examines further arguments for this connection; we evaluate a battery of more formal diagnostics under which the Brazilian Portuguese data pattern similarly to canonical instances of prepositional marking across Romance (Romanian, Spanish etc.). The application of other tests weakens the assumption of a unique licensing position for differentially marked objects in Romance languages Ver menos