Add a line, arrow, or shape Choose Tools > Comment. Draw in the PDF: To edit or resize the markup, select it and drag one of the handles to make your adjustments. To add a pop-up note to the markup, select the Hand tool, and double-click the markup. (Optional) Click the close button in the pop-up note.

How can I mark on a PDF file?

How to annotate PDF files: Open a PDF in Acrobat and select the Comment tool. Add PDF annotations to your file. You can add text boxes and sticky notes, underline text, strikethrough content, highlight text, and more. Save your file.

How can I mark a PDF document for free?

If you want to markup your PDF documents for free, this is the application for you. Nitro Reader is one of the best free PDF markup software that is very useful for all basic tasks that you perform every day with your PDF documents. You can also use it to create PDFs from scratch.