This powerpoint reviews which verbs require a Y in the él/ella and ellos/ellas endings, which verbs don't require a Y (and are regular), and which verbs are stem-changing, then students have to categorize verbs as a class. The powerpoint includes animation and is saved as both .ppt and .pptx.
This powerpoint is included in my Spanish Preterite -ER, -IR, Y, and Stem-Changing Verbs Lesson
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Spanish Preterite -ER, -IR, Y, and Stem-Changing Verbs Writing Activities