I have a trial version of Acrobat Pro DC and am doing a proofreading job that requires changes to be seen, but at present they are not. My question is: can they be seen? If so, how? And if not, which program with a free trial can I use to do so? Thank you.
Acrobat is not a word processing application, and should not be used as such. That's why it doesn't have a "Track Changes" function.
The correct workflow would be to add comments to the PDF and then send it back to the authors. They would then apply the changes in the original file format and generate a new PDF when done.
I have just worked out what I was omitting to do, I was using edit but I should have done it in "comments", where you can see what has been done (when I say track changes, that's what I was alluding to). So it's all solved, thank you.