The acquisition of Differential Object Marking in Spanish

In this paper, I show that a constraint-based approach to DOM, such as the OT system proposed by Aissen (2003), leads to the conclusion that the child will entertain a number of grammars different from the target grammar, before acquiring the final ranking of constraints, even under the learnability assumptions of the OT framework (such as those made by Tesar and Smolensky (1998, 2000). The data examined here, from Spanish-speaking children in the CHILDES database, clearly shows that children master Spanish DOM with a performance virtually errorless. This raises doubts regarding the capacity of the OT framework to explain a key aspect of human language, namely, the process of acquisition.