How to add comments to Google spreadsheet cells?
Comments can be added to each cell using Insert comments option.
Step 1: Insert the comments using any of the following two options.
Step 1: Select the cell and right click.
Step 2: Choose "Insert comment" option.
Step 1: Select the cell.
Step 2: Click Insert → Comment
Option 3: Press Ctrl+ Alt+M.
Step 3: Enter the comment in the box provided and click Comment to post the comment.
Step 4: Comment is added for the selected cell and marked with the small orange color arrow at the top right corner.