How to Undo the Ignore All Command in Word 2013
Click the OK button to return to your document.
By following these steps, you direct Word to un-ignore not only all previously ignored words but also any grammatical errors you've chosen to ignore. You have no way to undo this command, so think about it before you do it.
The steps for undoing the Ignore All command affect only the current document. The Ignore All command affects only the current document.