Software for adding/writing notes on a PDF?

My friend sent me a book he’s writing and wants feedback as I read. What’s the best software to add typed notes next to the pages and also easily underline/highlight stuff?

I think any PDF editor can handle this for free. It’s just a basic note/comment feature.

Edge can do both (add text and highlight) for free. If you want more features, PDFXchange or FoxIt PDF are good options and cheaper than Adobe.

i appreciate a lot…thanks

By the way, PDFXCE offers free annotation and some other features too.

With Adobe Acrobat Reader DC, you can easily highlight, underline, and add comments on PDFs, making it great for detailed notes, and you can share everything with your friend in one place.

If the book is split into sections, Notion lets you add comments, highlight stuff, and organize your feedback neatly, with separate blocks for notes to keep everything in order.