Commenting tools are available only
in PDFs that have commenting enabled. PDFs in a review workflow
typically include commenting rights. You can use text edit comments in a PDF to indicate where text should be edited in the source file. Text edit comments do not change the actual text in the PDF. Instead, they indicate which text should be deleted, inserted, or replaced in the source file from which the PDF was created.
You can use the Select tool or the Text Edits tool to add most types of text edits. Shortly after you click or select text with the Text Edits tool, an icon appears. If you right-click this icon, a menu of text editing options appears.

Replace text
Add a note to a text edit
from
the Comment & Markup toolbar.
Show inserted text
from
the Comment & Markup toolbar.Type the text you want to insert.
To indicate that a new paragraph should be added,
press Enter or Return, and then close the pop-up note without adding
text. The paragraph insertion caret
appears.
To
indicate that a space should be added, press the spacebar, and then
close the pop-up note without adding text. The space insertion caret
appears.
You can also indicate text edits by using the Select
tool
to
select text, right-click/Control-click the selected text, and then
choose Replace Text (Comment).
Delete inserted text
.
Delete text markups
If markup comments are stacked, delete
the comments in the Comments list: Click the Comments button in
the navigation pane to open the Comments list, select the comment,
and press Delete.
Do
one of the following:Select the markup and press Delete.
Right-click/Control-click the markup, such as the highlighting or cross-out, and then choose Delete.