This is a little cheat sheet or reference sheet for the preterite and imperfect tenses. It condenses a TON of information into four pages. In includes conjugations (regulars, irregulars, and stem changers and car/gar/zar verbs for the preterite) and uses of each tense. It also includes some key words/phrases that indicate which tense should be used. This would be a valuable sheet for students who are already somewhat familiar with the preterite and imperfect.
It is a Word document and can be edited to include words and information you want. The thumbnails look goofy because of the formatting, but everything should look fine when downloaded!