This dissertation aims at examining the possibility of taking the obligatory expression of verbs arguments as an index of Specific Language Impairment (SLI) in Brazilian Portuguese (BP) and at providing a clinical criterion for SLI diagnoses on the basis of this analysis. A further goal is to enlarge the sample of children with language problems whose linguistic performance is assessed by means of a set of tests (Modules for the Evaluation of Linguistic Abilities) that has been developed in LAPAL (Laboratório de Psicolingüística e Aquisição da Linguagem), in order to identify those aspects of language that are particularly affected in BP. Children with a probable diagnosis of SLI and normally developing children from 3 to 5 years of age constitute the sample. Seven experiments were carried out by means of an elicited production task, which aimed at evaluating the expression of the arguments of the verb -- external argument (subject) and the internal arguments (direct object, indirect object), as well as adjuncts. The results suggest that children in the SLI group have difficulty in the syntactic computation of the verbs argument structure, which is particularly manifested in the omission of the subject argument in an obligatory context. It is concluded that subject omission in the obligatory context characterized here can be taken as an index of SLI in BP.