How to Undo, Redo, and Repeat in Google Sheets
You're going to make mistakes at some point when you're using Sheets. When this happens, you can use the handy undo command to instantly undo your last action. The related redo and repeat commands are also useful and powerful.
To see how they work, you first need an action that you can undo.
Press Ctrl + Z.
Your last action is undone. For example, if you had deleted an item and then decided you wanted to keep it after all, undo would make it reappear.
Press Ctrl + Y.
The last action you undid is redone.
The last action is repeated for the selected cell.