Adding text fields and other form elements to create editable PDF forms in Adobe Acrobat Professional XI is a straightforward process. These elements create an interactive document that is ...

How to Edit Text in Adobe Forms. In most cases, Adobe PDF files contain static data, not intended for other users to edit. PDF forms, however, can have editable text boxes, allowing you to fill ...

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.