Project 3 of the GUME research project on foreign language teaching methods, in line with Projects 1 and 2, questions whether the best effect in language teaching is achieved solely by intensive drilling of the structure in question (the implicit method) or if grammatical explanations further the assimilation of the patterns so that, within the same period of time, the student learns better with fewer drills because explanations are added (the explicit method). Whether the explanations should be in the source language or the target language is also investigated. The educational problem of the experiment is teaching the English passive voice to Swedish students, aged 13 to 14. The main results of this experiment show that there are no significant differences between the three teaching strategies used. Details on the experiment are provided here; project design, subjects, teaching materials, evaluation techniques, student and teacher attitudes, and statistical results are discussed. A bibliography is included and appendixes provide details on grammatical explanations provided and on evaluation and attitude measurement techniques and results. Related documents can be found through the following reference numbers: Project 1, ED 034 172; Project 2, FL 002 818; Project 4, ED 045 969; Project 5, FL 002 814; Adult Project, FL 002 868; Statistical synopsis of Projects 1-3, FL 002 816. (Author/VM)