Theoretical implications of children's early production of Romanian Accusative clitics

• We use language acquisition data to shed light on the first Merge of clitics.
• We compare the acquisition of 3rd person to that of 1st/2nd person object clitics.
• Early post-verbal cliticization is a micro-step in the derivation of object clitics.
• The acquisition stages offer evidence that all object clitics Merge in the V-domain.
• Both 1st/2nd and 3rd person object clitics establish their reference in the derivation.

This study examines the acquisition route of object clitics with a view to identifying to what extent language acquisition data can shed light on the old debate with respect to the first Merge position of clitics: in the V-domain or in a higher position in the functional layer of the clause. The analysis of three longitudinal corpora of monolingual Romanian and the results of two elicited production tasks reveal an early stage when Accusative clitics occur exclusively in post-verbal position followed by a stage when the production rate is higher in post-verbal than in pre-verbal position. Building on the assumption that acquisition stages are ‘intermediate’ grammars which represent sub-grammars of the adult system, we argue in favour of a first Merge position of object clitics in the V-domain. In support of this claim the results obtained in a task eliciting the production of 3rd person Accusative clitics as well as the response pattern in a 2nd vs. 3rd person accusative clitic production task reveal an effect on early clitics of feature mismatch between the antecedent of the clitic and the subject of the clause.