The relative effectiveness of tutoring for both partners was examined by comparing tutoring with other learning activities that differed either in the amount of exposure to the learning materials or the presence of a helping relationship or both. The subjects were 160 undergraduates who were evaluated on their acquisition of Esperanto. Subjects who were given previous exposure to Esperanto did significantly better on the final test than those without such exposure, but being a tutor was no more beneficial than studying Esperanto alone. Although tutoring was not differentially effective in terms of overall achievement, four tutoring behaviors were found to be predictive of the achievement level of the tutoring pair: (1) tutors elaborated and brought in new information; (2) tutees asked their tutors what was important for them to know and remember; (3) tutors did not ask tutees what they did not understand; and (4) tutors did not give tutees incorrect information. It is suggested that the focus of future research should be on the effectiveness of specific tutoring behaviors. (Author/JD)