Tesis para optar al grado de Magíster en Lingüística mención Lengua Inglesa / Grammar teaching has been an area of considerable debate in the fields of Applied Linguistics and SLA research, fact that is reflected in the different choices EFL teachers have to make regarding methodologies and techniques in the classroom. As far as teaching practice is concerned, approaches to grammar based on traditional models have been widely accepted and adopted. Nevertheless, a series of shortcomings have been pointed out in current research, such as a considerable degree of arbitrariness, imprecision and contradictions. Alternatively, Cognitive Grammar in recent years has been gaining ground as a theory that may serve as basis for new methodological proposals. The present work intends to compare and contrast a rule-based approach to a cognitively-oriented one applied to the teaching of grammar. More specifically, both methods will be applied to the teaching of English conditional sentences. The aforementioned constructions have been selected given the complexity of the structures themselves and the oversimplification in their description that has been found in the literature. In order to achieve the goal set above, 36 university students divided into two distinct groups were instructed English conditionals following a rule-based and a cognitively-oriented methodology, respectively. A test common to both groups was applied afterwards with the objective of collecting the necessary data, in order to account for the degree of attainability of the constructions in each group. Such attainability was measured in terms of the grammatical criteria of tense, aspect, and modality contained in each type of conditional sentence. Quantitative results showed similarities in both groups regarding global results, hence the necessity to account for qualitative differences among participants in terms of their specific performance in each of the requested tasks.