The relationship between the realization of the argument-structure of a verb and its acquisition as a lexical item was investigated in a case study. The subject was a girl aged 2.3 years whose father was a native English-speaker and whose mother was a native Japanese speaker who also spoke English. The child had been born in the United States but had just moved to Japan and begun to speak Japanese. The language corpus used was recorded in the girl's home. English verb acquisition was examined. Analysis of the corpus suggests that children drop arguments of verbs in the course of acquiring argument-structure, and that they notice the obligatory nature of a phrase bearing a certain semantic role. It is concluded that children can solve the problem by indirect negative evidence, which is assumed to be necessary only for the acquisition of a special class of verbs. Further, it is shown that children do not examine the obligatory nature of all phrases, but only those that do not conform to a particular construction, which the children are able to set up in order to acquire verbal argument-structure easily. A brief list of references is included. (MSE)