Hi, I seem to be struggling with the reply mechanism. When I reply to a post it doesn't come indented underneath the post I replied to. It rather comes as a separate thing (as if it were a whole new discussion). I then tag the person I'm trying to reply to without really knowing if they got the initial reply notification I intended to send.
Just select a fragment of the post you are replying to and press "Quote" in the popup menu like I just did. Replies are not shown under the post you are replying to but in a chronological order, however if properly quoted you can quickly go from a reply to the post it is quoting.
No need to tag explicitly; I am automatically notified about all posts in a topic if I created it or (as in this case) replied to a post in it. I'm also getting a badge indication when I am getting replies, likes or tags.