This thesis investigates how children acquiring Brazilian Portuguese (BP) identify recursive structures in the complementizer phrase. It is assumed that children identify grammatical information based on the interfaces between the internal language and the systems related to linguistic performance. Recursion is a property of the language system which allows humans to build an infinite set of complex syntactic objects from a finite set of lexical items and syntactic operations. BP allows recursion in the highest node of the hierarchical structure (C - complementizer), building completive clauses. Structurally, completive clauses occupy the position of the complement of a verb and are introduced by a complementizer. The theoretical framework of this thesis is a procedural theory of language acquisition that reconciles the phonological bootstrapping hypothesis (MORGAN AND DEMUTH, 1996; CHRISTOPHE et al, 1997) and minimalist assumptions (CHOMSKY, 1995, 1999, 2005; HAUSER, CHOMSKY AND FITCH, 2002), as in Corrêa (2009a; 2009b; 2011). Two groups of experiments are reported, which focus on possible cues to the identification of a recursive structure, namely: the phonic form of complementizer and the structure of the completive clause. The results indicate that, although there is no conclusive evidence that children are sensitive to the presence of the complementizer due to its phonic properties, children, at 12 months, are sensitive to the structure of the completive clause, thereby suggesting that they go beyond the phonetic interface and start to be able to process subcategorization relations.