The Underline tool lets you place a line under the text. To use the highlight tool, select it in the toolbar, and then select the text that you want to highlight. The highlight tool lets you add a background color to draw attention to specific text. After typing your comment, select the Post button.
Your cursor will move to the Comment pane where you can type your comment. To use the sticky note tool, select it in the toolbar, and then click the spot where you want the note to appear. The sticky note tool lets you “stick” a comment anywhere on the page. Now, let’s look at the thirteen tools in the Comment toolbar. Comment toolbar and Comment pane How to Use the Comment and Markup Tools in Adobe Acrobat The Comment toolbar will appear directly above the PDF, and the Comment pane will appear on the right side of your screen. How to Access the Comment and Markup Tools in Adobe Acrobat Unfortunately, you cannot change this option if the creator of the PDF has set Commenting to Not Allowed. Then, see if the Commenting option is listed as Allowed. To find out if commenting is allowed in your PDF, select File > Properties > Security.
These tools are also available in Acrobat Reader when commenting is allowed in the PDF.
