Keynote Help :Undo or redo changes
Undo or redo changes You can undo any changes and redo them if you change your mind. Undo or redo actions Undo the last action: Choose Edit > Undo (from the Edit menu at the top of your screen), or press Command-Z. Redo the last action you undid: Choose Edit > Redo, or press Shift-Command-Z.