[header] How to use the undo and redo commands [title] Shake your iphone or ipad. [step] Doing so opens a dialog box asking if you want to " undo " the action you just performed. [title] Tap undo. 
[step] The last action you performed, such as typing, cutting, copying, or pasting, will be undone. [substeps] Alternatively, on ipad, tap 123 in the lower-left part of the keyboard, then tap undo [title] Shake your iphone or ipad after an " undo " action.