2014 Spring.How and when to use the preterite or the imperfect is one of the most common issues that Spanish language learners face in the foreign language classroom. Most of the times, textbooks present students charts in which the use of each tense is listed. Nonetheless, this generalization doesn't take into account one of the most important aspects necessary to determine when to use the imperfect or the preterite: The speaker's intention. This thesis purports to show that more than memorizing a list of common uses, it is very important that students analyze the perfective or imperfective aspect of the action presented. Additionally, some examples were taken from two textbooks (Aventuras (2010) y Experience Spanish (2012)), and they were studied in order to prove that the lack of context produces ambiguous sentences that generate confusion among the students
