What I would do is download the pgn (using Get pgn)and then paste this into an application on my computer. On my mac I use something like chessX which is free. I can then go through the game move by move and insert comments. When I am finished I copy the pgn file from chessX and insert it back into here using the chess icon.
I think there may be other ways of doing it but that is how I do it.
I just saw someone post this which I was unaware of:
The Game Editor on this site is a perfectly good PGN editor - select More at top of any page & click on Analysis Board & Editor on the drop-down menu.
Select 'Game Editor' mode & you can then paste in your PGN file - it's not possible to directly import a PGN file into the Editor or save it (open it first in any text editor but remember to select the 'all file types' option). Then you can step through the moves & add/edit/delete any of the comments.
When you've finished, you can save the PGN by choosing the 'Copy PGN' option & then copy/paste it back into your text editor & from there save it to your PGN's folder ?
It seems you can do everything on chess.com
WHen I click on More, Analysis Board and Editor is ont one of the options. Is it under one of the sub options?
Never mind. it is actully under 'Game Editor'.
copy someone's board but set it so that I can intert comments into it ... (ie to respond to someone's request for advice on a game by copying the game). Thanks!