Actually, you can write on pdf files with just acrobat reader, which is a free download. However, you cannot save what you wrote. You just fill it in at one time and then print it. If you want to be able to save what you wrote, you need the full version. And you don't have to convert it to a Word file in that case, you just save it as a pdf file. But that way, you can fill in a little, save it, close it, and come back and do more later.