You can reply to a person also by using: @ username (i.e. @ Frank).
If you want the person to get a notification that they have been quoted, then quote the post, delete the text and leave only the name of the user and the quote code/html like that: [q u o t e="Δύναμις"][/q u o t e] I added the spaces between the letters here so you can see what it should look like. Without the spaces it becomes this:
Δύναμις wrote: