how did you post this response so beautifully? i had such a stupid time trying to figure out how to respond to your reply on my post, i must learn how!
I only figured out how to do this pretty recently, actually! I shall explain with pictures!
First I copy your response like so (pardon my fluorescent green highlight)

and then I go up and make a text post and paste it - it’ll look funny, but for whatever reason tumblr doesn’t really care and will make it essentially plaintext.

this step is important:

if you don’t press the quote mark, it’ll keep writing in that format. It’s very strange.
I really wish tumblr had better comment features, not gonna lie.