How to Add Comments to a PDF With Acrobat Reader. PDF files enable you to share and comment on content created in a wide range of applications. Adobe Reader, formerly called Acrobat Reader, offers ...

Need to edit a PDF document but don’t want to pay for the more expensive Adobe editors? You can add text to and sign a PDF with just the free Reader program.

In other words, Adobe Reader won't let you add text. What you need is a program that's a little more accommodating, PDF-wise. Try Foxit Reader 4.3, which allows you to add text to any PDF.