There is much for students to learn, memorize, and practice when it comes to the preterite tense. It is typically helpful for students to think of preterite verbs in distinct categories and then to learn and apply the rules for that category. Below are the various categories (new stems and verbs with “y” and “í” are not complete lists, only some of the most common). The new stems category on its own is fairly complex, and thus in that storyboard template you will find more details on how it works.
These storyboard templates and activities are designed to help students practice and internalize these categories and patterns, as well as put the preterite forms into context with an eye towards their meanings.