DRILL IT! Mastering Pretérito vs. Imperfecto by Rosa Luna is the ultimate all-in-one guide for Spanish learners determined to conquer the most notoriously tricky grammar challenge in the language: knowing when to use the preterite and when to use the imperfect. Spanning 179 pages across four comprehensive parts, this book takes you from clear, intuitive explanations of each tense — complete with conjugation tables for every verb type, regular and irregular — through hundreds of real-world examples that show exactly how native speakers think about the past, and then plunges you into over 1,000 carefully designed exercises that drill the distinction into your bones. You'll tackle fill-in-the-blank sprints, multiple choice marathons, error hunts, sentence transformations, paired contrast analyses, contextual judgment scenarios, cloze narratives, full paragraph translations from English to Spanish, rapid-fire conjugation challenges, and six comprehensive timed exams — all progressing from beginner to advanced, and all featuring the meaning-changing verbs like saber , conocer , querer , and poder that trip up even intermediate students. Every single exercise includes a complete answer key with a brief explanation of why each verb is preterite or imperfect, so you're never left guessing. Whether you're a student preparing for an exam, a self-learner pushing toward fluency, or a teacher looking for a rich classroom resource, DRILL IT! gives you the depth, the repetition, and the variety you need to stop translating and start feeling the difference.