Stem changing verbs: O>UE
One of the forms of stem-changing verbs is called O to UE. That's because the O in the stem of the verb changes to UE in all of the forms except vosotros and nosotros. Some folks call stem-changers "boot verbs" or "shoe verbs" because of the way they look on the verb chart. Use these resources to learn more.
Online activities from the Realidades textbook
Book 1 Chapter 6A p. 284
Music videos and activities for practice
Online Grammar Lessons with worksheets