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.

The free version of Foxit PDF Reader lets you add a text box to your PDF files. To do this, follow the steps given below: Open the Foxit PDF reader interface Access the File menu, then Open, and ...

Foxit PDF Reader is a free document viewer that supports advanced annotation tools. This lets you control the size, color, and style of inserted text or shapes.