- In the Word 2010 document, click or select the text where you want to add the comment.
- Go to the Review tab and then click the New Comment button.
- You will notice that the text you clicked or selected now is highlighted and a comment balloon will appear. Type your text in the comment balloon and that is it! If you have many comments you can easy navigate with the Previous and Next button in the Comments section in the Review tab.

Removing a comment in Microsoft Word 2010 document:

Also it can be useful to view the comment in the left side of the document.
- Go to the Review tab.
- Click the Reviewing Pane button and now all the comments will be also display in the left.
- To remove the Reviewing Pane, just click the Reviewing Pane button once again.

Bonus
If you need to respond to a comment that was added to the document, the only thing that you need to do is to click the comment, click the New Comment button, and add the text.
I hope this simple tip working with Microsoft Word 2010 was useful to you!