Never ever. I don't know why, but I just can't stand the idea of writing in my books. I don't care if its spine is broken or the book is otherwise damaged, the inside must be clean and untouched.

But I tolerate you all, as long as you don't underline stuff in mine when I lend them to you

I always want to keep my books totally clean

Yes I mark mine up, surprised so many here don’t. I used to be a person that never did, but heard some people on podcasts highly recommend it, and I also began wanting to take notes. I think it adds value to the book on a re-read if you do it cleanly. I underline the first and last word of the highlight, with a curly bracket in the margin to indicate the area (sometimes a comment added), and a small plus sign in the top right corner to indicate which pages are noted. Then I can flip through when finished and dictate the notes to my computer. But they also make sticky tabs for page notes if you don’t wanna mark books up. I do have some visual or big coffee table books, like Poor Charlie’s Almanack, that I don’t want to mark up inside.

No

If it's my own book then yes -- I'll underline and make notes (but always with pencils, never pens!)

I also use dog ears, that's just how I roll!

I want to be the person who reads attentively, underlining things and scrawling notes in the margins, then going back to reread years later, or share books with others who do the same. But I always get too caught up in the story, or just cant bring myself to do it when I do remember. It also slows down my pace of reading quite a lot, and I'm not that fast to begin with.

It doesn't help that, as a librarian, the people who write in library books are the worst!

I do!

Oh hell no.

I was brought up with the concept of books being the secular equivalent of sacred. I still cringe at the idea of anyone ever throwing them away - and notes/underlines/doodles/dogears/etc still feel like unspeakable vandalism to me.

That's not really a defensible attitude - books are just tools, physical books are just printouts of the text, terrible books don't deserve space in my home, and there's something unpleasantly religious about treating them as untouchable.

But the conditioning goes deep, and it's hard to unwire.

I read ebooks 90% of the time now, rendering the question mostly moot - but my eyelid still twitches when I see someone hold a book folded back on itself.

Absolutely not!! Post its and such plenty but no markings

That's what I like about E-books, this isn't even an issue. I only buy physical copies for books that I specifically want to own in such format, in which obviously I won't write or underline anything.

I always want to, but I just can't stand to see the clean book merged with my shitty handwriting

I've made a few attempts, but it feels so very wrong. Defiling of a sacred object, almost.

I plan to find some older second-hand books with markings already made by others and see if that dissolves the mental barrier. Perhaps it may be made easier if it is a copy of a title I already own.

I always use clear sticky notes for highlighting and underlining, kind of gives the same experiencing as actually writing on it

No doodles, but when I had physical books I would I highlight and make comments in the margins.

In ebooks I use the highlight/addnote functionality.

No. However, I use stickers to mark parts I want to get back to and that I find inspiring. I also write on stickers.

The idea is sort of romantic .. But in pratice writting on my books feel like could ruin the experience for the people I share my books with so I don't. But i well loved book with a lot of wear is absolutely lovely

I underline or highlight things that I think are important or interesting. It makes reading back a lot more interesting, almost like a little window into what past me was thinking about.

No way, books are sacred. I stopped dog earing them when I was 15.