A study undertaken in Ireland investigated the effectiveness of a second language teaching strategy that focused on grammatical problem-solving. In this approach, the problems are located within the target language system, and the problem-solving involves induction of grammatical rules and use of those rules. Learners are confronted with instances of a specific grammatical problem, from which they induce a generalization about form and function. They are provided with tools for solving the problem, such as examples, hints, and feedback. Learners are then given opportunities to use the rules to confirm them, observe how the new rules interact with others, and explore relationships between linguistic structures and their communicative values. Subjects were approximately 100 secondary school graduates, all foreign nationals, attending pre-university courses leading to the Irish school leaving certificate examination. Participants were placed according to ability level and randomly divided into experimental (problem-solving) and control (conventional grammar instruction) groups. Instruction covered six topics of grammar: articles; quantifiers; past simple vs. present perfect tense; logical connectives for addition, contrast, concession, and cause/effect; relative clauses; and passive voice. Experimental subjects found the approach effective and relevant and achieved greater gains in both competence and performance than did control subjects. (MSE)