LibreOffice Writer can create fillable PDFs from scratch with built-in tools. Start by opening a blank document and adding form fields using the Form Controls and Form Design toolbars. To export as an ...

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.

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.

This post helps to add a text box to PDF using a free software and an online tool. You can adjust the size of text box, text style, etc.

macOS added an option to try to identify fields in a PDF form so you can easily enter text or check boxes.