This study presents the procedures and results of an experiment conducted in Sweden to assess the relative effectiveness of two methods of teaching the grammatical structures of English as a foreign language to adults. The main objective of the study is to find indications as to which of the two theories (the audiolingual habit theory or the cognitive code-learning theory) provides a better basis for teaching foreign language grammar to adults. Chapters examine experimental objectives, existing research, teaching methods, comparative studies, experimental design, evaluation instruments, and project results. Appendixes contain sample instructional materials, charts illustrating distribution of lesson time, evaluation instruments, and information about the Swedish school system. Lists of tables and figures are provided. (RL)