Since general principles of first language acquisition and environmental input have been clarified by research of the last decade, more differentiated questions are explored in the present study. The main goal is the investigation of similarities and differences in the language teaching and learning processes involved in the verbal interactions between mothers and children. A concomitant focus lies upon the differential description of the sequential relationships between maternal input types and filial acquisition strategies. Two mother-child dyads were studied wherein the children were approximately matched in mean length of utterances which ranged between 1,5 and 4,0 morphemes. The ages of the children ranged between 18 and 35 months. Thirty-nine maternal teaching techniques and 37 filial learning strategies were differentiated and their sequential dependencies were studied. The structure of the interactions was described quantitatively by means of transitional probabilities and by contrasting the observed frequencies with expected ones. The import of the interactions was also tentatively interpreted on the basis of linguistic, instructional, and psychological principles. Although wide quantitative differences between the two dyads were found, it appeared that the two middle class mothers had adopted qualitatively similar strategies. The two children, however, seemed to follow qualitatively divergent approaches in their strategies of language acquisition. (Author)