I usually click "reply" and it quotes the whole post in the box where I can type a reply.By the way how do we quote? I press the quote button it just said quote +1 but I don't know what to do next to choose a specific sentence.
I click inside the quoted area to delete parts of it, leaving just the part I want quoted. Or I hit enter a few times to add some space, and it splits itself into several quotes, so I can respond to different pieces separately.
I click outside the quoted part so I can type my answer there.
I am doing this on a desktop computer, typing with a keyboard. I know some people use a cell phone, or use voice-recognition and speak their responses, or various other ways of interacting with the site. They may have to do things differently than I do.